thin air. >> i want her back! >> this has turned, the story. >> her family said she was being sexually harassed by a superior. this kicked off the hashtag, i am vanessa guillen. >> want my sister. >> women are coming forward saying that you were sexually harassed in the army. >> enough is enough. we need to change this. >> the trends are going the wrong way, it's really tearing at us as an institution. >> a man who is out digging holes sees what he thinks is human hair. >> miracles can happen, i will say, please don't let it be -- hello and welcome to dateline. vanessa was living her dream while keeping close to airtight knit family and serving in the military. then she disappeared. as soldiers search for the missing soldier, -- their quest for answers would shine and spotlight on an ugly truth. but would it lead them to vanessa? here's "voices for vanessa". >> i couldn't believe this is happening to me. it was the scariest part of my life because i was alone. >>reporter: so many were quiet for so long. >> i was harassed, sexually assaulted, raped and physically threatened. this man that i physically trusted, i felt violated and stupid. >>reporter: but now they want to be heard. >> the man who sexually assaulted me are still serving in uniform. >> there is no excuse for harassment, it has to stop. >>reporter: all these voices inspired by one that suddenly went silent. >> april 22nd, 2020, should have been a easy wednesday for private first class vanessa guillen. she was heading to complete a few tasks that her boss had texted her about. even in this regimented army world, fc guillen texted a lot with her friends, boyfriend, and constantly texted with her mother gloria. >> my mom was texting her every other hour. what are you eating? are you okay? >>reporter: so we strange wind by midday, the tech stopped appearing. >> the call went straight to voice mail. the message didn't send. i tried calling again. it went to voice mail. that's when i started getting really scared. >>reporter: vanessa guillen was it typically american one. the daughter of immigrants, 1 of six children, she was a mix of many things, generosity, ambition, humor. >> when no one was watching her, she was with her family. what was your personality like? >> she was goofy, she laughed at herself. her laugh was contagious. >>reporter: according to her mother gloria, even as a child, vanessa was laser focused. >> is it true she wanted to be in the army as young as ten years old? [speaking spanish] [speaking spanish] >>reporter: by high school it looked like vanessa would have plenty of options in life. her friend ashley said sports were her thing. >> she was always exercising. >> was she the whole package in high school? >> she was friends with everyone she encountered. >>reporter: as graduation neared, vanessa told her family she hadn't changed her mind. she still plan to enlist in the army. >> she wanted to help others, she wanted to have better opportunities. >>reporter: after basic training, vanessa was assigned to fort hood in killeen, texas. there she specialized in small arms and artillery repair. vanessa made friends, things went well, she received great feedback from superiors. on weekends she would make the three hour drive to visit her family in houston. but a few months in, her family noticed a change. >> [speaking spanish] >>reporter: gloria asked her daughter what was wrong. [speaking spanish] >>reporter: now, a year later, vanessa had gone off the family radar. as the days past, her silence nagged at myra. of course, she could just be busy with work. still, it wasn't like vanessa to disappear. the problem was, we are to look for her? >> for who it is one of the largest army installations in the world. >> >>reporter: jasmine caldwell reports four kcen tv on fort hood. >> it has 214,000 acres. there's about 65,000 soldiers, roughly. so it's a very, very large place. >>reporter: myra agonized. the place was so large, her sister could be forgotten easily. and she didn't like what she heard when she spoke with one of vanessa staff sergeants. >> he wasn't able to tell me anything. that made me even more upset. >>reporter: too upset to sit home and wait. >> you had to fourth could? so you needed answers? >> right. >>reporter: myra says she was surprised by the reception she got the gate. >> what did they tell you? >> they tried to ask me if i knew anything. i'm like, if i knew anything, i wouldn't be standing here. >> so this is a mystery? what happened to your sister? no one knows anything? >> everyone claims that they just didn't know. >>reporter: army investigators did tell the family one terrifying thing. >> everything was their, her car, her keys, credit, debit card, ideas self. her military i. d.. she would never leave without it. >> that is extremely bizarre, that she is gone but all of these critical items that, of course, any soldier would have. especially the i. d.. it's there. what did that tell you? >> that's something really bad happened to her. >> how did she just disappear? >> exactly. >> coming up, how does someone just disappear from a military base? >> my first thought. she must have went awol. >>reporter: then the last images of an essay before she went missing. picking up food at a local restaurant. >> the owner said it seemed like she was worried about something. >>reporter: and vanessa sister uncovers hidden dangers. the armies problem protecting their own. >> i was like, what's happening in fort hood? >>reporter: when "dateline" continues. more carbs?" before you decide... with the freestyle libre 2 system know your glucose level and where it's headed. no fingersticks needed. manage your diabetes with more confidence. and lower your a1c. the number one doctor prescribed cgm. freestyle libre 2. try it for free at freestylelibre.us dupixent helps you du more with less asthma. and can help you breathe better in as little as two weeks. dupixent is an add-on treatment for specific types of moderate-to-severe asthma that's not for sudden breathing problems. dupixent can cause allergic reactions that can be severe. get help right away if you have rash, chest pain, worsening shortness of breath, tingling or numbness in your limbs. tell your doctor about new or worsening joint aches and pain, or a parasitic infection. don't change or stop asthma medicines, including steroids, without talking to your doctor. ask your specialist about dupixent. ♪ you're the one that i want! ♪ your dog is the one you wanted. you want what's best for them. ♪ ohh, ohh, ohh! ♪ so ask your vet about new nexgard plus. it's one-and-done monthly protection from fleas and ticks, plus heartworm disease, roundworms, and hookworms... all in a delicious, beef-flavored, soft chew. use with caution in dogs with a history of seizures or neurologic disorders. from the maker of #1 vet-recommended heartgard plus. nexgard plus: the one you want for one-and-done protection. after advil. feeling better? on top of the worlddddd!!! before advil. advil targets pain at the source of inflammation. when pain comes for you, come back fast with advil liqui-gels. 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(vo) visit mytepezza.com to find a ted eye specialist and to see bridget's before and after photos. on april 24th, two days after on april 24, two days after vanessa guillen's vanessa guillen's disappearance. the army released what's called a be on the lookout notice. at first, jasmine caldwell of kcen tv didn't pay much attention to it. >> it happens often. my first thought? she must have went awol, just swept it under the rug. but then the next day, you know, it wouldn't go away. it was like, let's look into this. >> vanessa's family and friends are determined to find her. >>reporter: what caught jasmine 's eye right away was the determination of her family. >> you didn't leave the area. you stayed. >> we weren't going to leave until we know something. until we find her. i know she's with us, i can feel it. >> by now, fort hood had dispatch soldiers to look for vanessa. local, state and federal law enforcement help. but as the number of days without vanessa grew, the family wondered if the search lacked urgency. so they kept pressure on investigators and searchers, even looking for her themselves. >> it's a matter of time before somebody, you know, actually confesses something. or we find a way to find her ourselves. >> we were searching anywhere, printing posters, putting them everywhere, calling people. >>reporter: dateline posted a missing in america article, reaching hundreds of thousands of people online. the family didn't let up. but they say the army wasn't much help. that they got very little information from fort hood. >> they were like, we can't help you anymore, because there's no information. there is no tips going on. but, that's your job. >>reporter: the family said their conversations at fort hood disturb them. they felt ignored, that the army wasn't sharing enough details, and that the search was still moving too slowly. >> we started protesting. telling them that we are not going anywhere, we are going to stay here until we find vanessa. >> i want her back and i want her alive. >>reporter: even at weekly rallies, intensified searches and weekly tv coverage, there was no sign of vanessa. >> a reward was posted, hundreds of people were searching. >> but weeks had gone by. and nothing. >> i still had faith. i had faith that we would find her. >> then, jasmine caldwell caldwell found what she thought was a clue. >> the owner of this mexican restaurant gave me surveillance footage. >> it was a vanessa before she went missing. >> you can see her getting out of her white jeep and going to get food. >> the last images of vanessa before she disappeared. >> the owner, moreno says that he knew her well. he said that she did not seem like her normal self, in fact it seemed like she was worried about something. >> our partner network went with her to the restaurant. >> [speaking spanish] >>reporter: for weeks the family had been trying anything, everything to find vanessa, including a big push on social media. >> we started a page, find vanessa. >>reporter: their facebook page was exploding. >> every day we will get 10,000 followers, 10,000 likes. >> it's getting national attention, so we just lived. we eat, sleep and breathe vanessa guillen. >> it was getting traction. >> we kept pressure up as a family, because we wanted answers. >> we are not in the fight alone. >> meanwhile, lupe began reading up on fort hood. she discovered a series of investigations into problems there. >> i read about two mess shootings. not only one but various prostitution rings. gang members. drug use. violence. i was like, what is happening in fort hood. >>reporter: in addition, fort hood has some of the highest murder, sexual harassment and sexual assault rates in the u. s. army. knowing that only made the family doubt the army officials more. nearly two months after vanessa disappeared, her family took a dramatic step. vanessa's mother said that vanessa told her secret. she said she had been sexually harassed by superior. the family went public on telemundo. >> [speaking spanish] [speaking spanish] >>reporter: vanessa's family was certain her disappearance was connected to sexual harassment. >> i don't know what's give someone the right to harass my sister. >>reporter: they demanded investigators get to the bottom of it. >> i your daughter, grandmother, would you like them to be sexually harassed? no. >>reporter: they revealed vanessa secret in hopes of solving a mystery. but they didn't realize that they just started a movement. >> one families tragedy unites a sea of strangers. and more secret spell out. coming up, outrage. and then an outpouring. >> this kicked off the hashtag, i am vanessa guillen. it was just flooding social media channels. >>reporter: stories of what some call the man's world of the military. >> i told kate, you really need to cut that out. and he said, why, what are you going to do about it. and in my mind i realized, i can't do anything about it. that was the lowest point for me. >>reporter: "dateline" continues. and he said, why? what are you going to do about it? and in my mind, i realized, i'm not going to do anything about it. that was the lowest point for me. andrea canning (voiceover): when "dateline" continues. attention hearing loss sufferers! do you struggle to hear loved ones? do you have trouble keeping up with conversations? do you listen to tv on max volume? 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>> a lot. like, how do you manage to do pushups with those? >> and where any of the comments hitting on you? >> oh yes. they would say, oh, no offense man, i want one of the good-looking ones. >> melissa said she had to be careful about how she reacted, especially with superiors. but if it was your superior who made an inappropriate comment, and you did snap back, what would happen? >> there would be a reprimand at that point, probably. there was a real fear of retaliation. but >>reporter: it wasn't just her superiors. >> i was in company command and i had a soldier make comments toward me. i told him, you know, you really need to cut that out. and he said, why, what are you going to do about it? and in my mind i realized, i can't do anything about it. that was the lowest point for me. >> wow. when you have that realization, that he's right, i'm not going to do -- that's a horrible realization. >> it was a horrible realization. this is someone who is reporting to me, who is essentially taking away my authority and my agency as a woman and also as an officer. and saying, you are not going to do anything about it. >>reporter: for bryant, the message was clear. taking on harassers could damage her career. is it fair to say that the military is still mostly a man 's world? >> very much so. it's changing but it's still very much a male dominated world. >>reporter: and while the military has set up programs like sharp, the army sexual harassment and abuse response program, reports of sexual harassment still rose by 10% between 2018 in 2019. higher numbers can partly be attributed to some members being feeling more comfortable reporting harassment and abuse. >> we want answers! >> as vanessa's disappearance turned into a cause, the family brought in a firebrand attorney named natalie khawam to get to the bottom of claims that vanessa was sexually harassed. >> they said, how much are you going to charge us? i said i'm not gonna charge you anything, you lost your daughter. >>reporter: is it possible they were doing all this for investigation but they were holding it because that's how they operate it? and they aren't going to share critical details in investigation? >> with a missing person case, you share information with the family. and i feel the reason they didn't want to share information with us was because they didn't want to be critiqued or questioned. >>reporter: major general donna martin conducted the criminal investigation division, which investigated vanessa's disappearance. >> i think there is an investigation misperception out there, that because we see some of these shows on tv, that evidence just turns up. it doesn't happen like that and we are life. >> how important was this investigation to you? she says behind the scenes, the investigation was more intense than anyone realized. she will take us inside it next. coming up -- >> they are searching their company areas, the installation, they are looking everywhere for vanessa. >>reporter: on base, a frustrating hunt for clues. any blood evidence? >> there are no signs of blood. >> no signs of struggle? >> no. >> it's like she vanished into thin air. >> almost. when "dateline" continues. arexvy is a vaccine used to prevent lower respiratory disease from rsv in people 60 years and older. rsv can be serious for those over 60, including those with asthma, diabetes, copd, and certain other conditions. but i'm protected. arexvy is proven to be over 82% effective in preventing lower respiratory disease from rsv and over 94% effective in those with these health conditions. arexvy does not protect everyone and is not for those with severe allergic reactions to its ingredients. those with weakened immune systems may have a lower response to the vaccine. the most common side effects are injection site pain, fatigue, muscle pain, headache, and joint pain. i chose arexvy. rsv? make it arexvy. hi, i'm jason. i've lost 228 pounds on golo. ♪ changing your habits is the only way that gets you to lose the weight. and golo is the plan that's going to help you do that. just take the first step, go to golo.com. >> the first aid convoy has finally answered, gossip 20 trucks carrying food, water, and medicine were finally allowed in. you can reps on the ground though say the delivery of 40,000 liters of drinking water represents a, quote, drop in the ocean in terms of what is still needed. and israel's military plans to expand its operations have been approved ahead of a looming ground incursion into gaza. idf official called on residents of northern gaza to continue evacuating to the south. now back to dateline. >> welcome back to "dateline". i'm andrea canning. vanessa guillen said she was sexually harassed before she disappeared from her army base. they're clean inspired other service members to share similar stories on social media. meanwhile, vanessa's loved ones worried the missing persons case was going nowhere. but it turns out, a breakthrough was just around the corner. continuing now with "voices for vanessa". >> i want my sister back and they want her life. >> we need answers. >> vanessa guillen's family and her supporters were convinced that the army had been negligent in its response to her disappearance. >> this investigation was absolutely the number one priority. >> general donna martin says the army was doing everything possible to fine vanessa, and a lot of soldiers were helping. >> over 500 soldiers turned out at this point. they're searching their company areas. they're searching the installation. they're looking everywhere for vanessa. >> and in the weeks that followed, she says for investigators chased down every lead. >> we conducted over 300 interviews with members from the unit, and soldiers from fort hood. >> she says investigators started by narrowing down a timeline of the necessary day. where she was and who she was with. >> every person who had an encounter with vanessa that day was a person of interest to us. >> vanessa's first encounter was at 10 am, any weapons storage and repair room, known as an arms room. she left personal items there with a soldier whose frankly specialist. >> so, we learned that specialist had spent some time with her and actually, because she had let those items in the first arms room, had an expectation that she would return. >> investigators learned that when vanessa left that room, she walked 75 yards to his second arms room. she met another specialist there sometime after 10:20. >> the specialist told us that vanessa had arrived at his arms room, and that she had conducted her task, and then she left. >> was there any reason to suspect that he had done anything wrong? >> no. >> in fact, vanessa texted her platoon leader she had completed her tasks in the second arms room, and three eye witnesses smoking under trees say they saw venice at 11 of 15. >> those soldiers told us, in an interview, that they saw vanessa move towards the parking lot. and so, because we knew her car was in the parking lot, we absolutely searched her car. >> was anything found in the car? >> no. >> investigators would end up bringing in a forensics unit to look for evidence. any blood evidence? any smell of cleaning supplies that with suggests that something had happened in one of those rooms? >> there are no signs of blood in the arms room. >> no signs of a struggle? >> no. >> it's like she vanished into thin air? >> almost. >> did you see anything in her personal life? any red flags? >> not at all. >> this is a responsible soldier? >> yes, absolutely. no information that would suggest she would walk away of her own volition. >> weeks went by. then the case shifted focus when investigators learned the soldiers, who thought they'd seen vanessa at 11:15, had been mistaken. they'd really seen her and our earlier, around the time she met with the two soldiers in the arms rooms. did either of these soldiers have any reason to kill vanessa? that you could gather? >> we have no information that will lead us either the soldiers had a reason to kill vanessa. >> even so, the specialist vanessa was with in the second arms room could have been the last person to see her a life. his name was aaron robinson, a 20 year old combat engineer. what was robinson's alibi that day? >> specialist robinson tells us that once he had met with vanessa, that he pretty much was done for their day. and so, he actually locked the arms room and he left for the day. >> robinson's personal i. d. was entered into the security system, indicating he'd left the arms room when he said he did. did he go home? >> that was his story. he told us he was home for the rest of the evening. >> and who was he with? >> cecily aguilar. >> cecily aguilar was robinson 's 22-year-old girlfriend. a civilian estranged from her husband. aguilar worked at a local gassed asian, but had a side business on social media, posting receive pictures of herself for quick cash. >> reporter jasmine caldwell learned from court records that aguilar told investigators pretty much the same story as robinson's. the >> night of april 22nd, she was at her home with aaron robinson. didn't know anything about the disappearance of vanessa guillen. >> but that was adding up for investigators. in court documents, the laid out an entire scenario of vanessa's disappearance using cell phone analysis. military reporter healy says the documents reveal revealed a night vanessa when missing there were multiple calls between aguilar and robinson. that seemed odd, because they both said they were together all night, at home. and the phones were both there? his and hers? >> right, yes. >> aguilar told investigators she could explain those calls. >> the reason he called her multiple times is because she couldn't find her phone and he was helping her find a. investigators knew that wasn't quite the full story, because the calls were longer than you would expect for someone just quickly calling to help you find yourself in. >> and a later interview, they confronted cecily aguilar with a location data that placed her phone about 20 miles from her home, mary river. >> at first she did confirm the story that she had been at home the entire night. she later backtracked and said they had taken a drive to de-stress, to look at the stars. >> if cecily aguilar the's story, seemed shaky to investigator, they became even more suspicious when search teams arrived at the river and made a disturbing discovery. >> so, they found what they described as a burn site. >> among the scorched trees were remnants of a big burned out plastic box called atf box. investigators had stumbled upon a huge clue. tough box of the arms o and was it enough to arrest him? in a case like this,>> that's ef itself, was not a real connection to specialists robinson at this point. >> investigators feared the worst, but they still couldn't prove anything. they had no evidence robinson had harmed vanessa. but nine days later, everything changed. coming up -- miles from the base, a heart stopping discovery. >> a man who is out digging holes hits cement. and sees what he thinks is human here. >> that is such a disturbing discovery. >> it's tragic. >> i can't bring, almost, please god, because miracles can happen. as they please, don't let it be. >> when "dateline" continues. i recommend sensodyne. sensodyne toothpaste goes inside the tooth and calms the nerve down. and my patients say you know doc, it really works. 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[music playing] ♪ you're the one that i want! ♪ your dog is the one you wanted. you want what's best for them. ♪ ohh, ohh, ohh! ♪ so ask your vet about new nexgard plus. it's one-and-done monthly protection from fleas and ticks, plus heartworm disease, roundworms, and hookworms... all in a delicious, beef-flavored, soft chew. use with caution in dogs with a history of seizures or neurologic disorders. from the maker of #1 vet-recommended heartgard plus. nexgard plus: the one you want for one-and-done protection. on june 30, more than a week vafter investigators searching. for vanessa guillen found a suspicious burn site and the remnants of a black box, contractors installing a fence in the same location stumbled upon something even more sinister. >>reporter: on june 30th, more reporter: investigators have found than a week after investigators searching for vanessa guillen found a suspicious burn site and the remnants of a black box, contractors installing offense in the same location stumbled upon something even more sinister. >> investigators have found partial human rains, about 25 miles southeast of fort hood. >> most of the investigative work has been happening that way. >>reporter: it was 69 days after vanessa disappeared. >> a man who is out digging holes in this area hit cement. and when he hit cement, he sees what he thinks is human hair. >> that is such a disturbing discovery. >> it's tragic. >> so she i. d. calls you and tries to do what? >> that they've discovered human remains. >> do you in your heart believe it's vanessa? >> i did. >> i kept praying, i was like, please god -- because miracles happen, i was like, please, don't let it be. >>reporter: an investigator later confirmed the worst with a single detail. >> he told me about her neck. >> how did he describe it? >> her long black hair. >> so you are the first in your family to learn this. how do you share the news with everyone else? >> i couldn't tell them. >> the body of vanessa guillen, the missing fort hood soldier, has been discovered. >> [speaking spanish] >>reporter: but she was dead. at just 20 years old, vanessa guillen had been murdered. >> vanessa was one of us. it was heartbreaking for all of us. >>reporter: hours after vanessa 's body was discovered, cecily aguilar was called in for questioning. and her story went to pieces. >> the moment we all wrapped together was when i cecily aguilar, confesses to authorities. she was robinson's girlfriend. according to a criminal complaint, that nighttime trip she said she made with robinson and gaze at the stars was just another lie. >> aguilar told investigators that robinson picture up from work and they went out to the river. she tells them that robinson told her that robinson told her that he killed a female soldier, and put her in a box and drove right to the river. >>reporter: aguilar said robinson led her to the box. >> when he opened it she saw vanessa guillen inside of it. and she told investigators that they then went forward to dispose of the body. they tried to burn the body, but it wasn't burning completely. and that's when they buried her remains into three separate graves in the area. >>reporter: as for the murderer self, investigators say it happened on april 22nd in the arms room where robinson worked. where there were no security cameras. >>reporter: did cecily say how long he had killed or? >> he hit her several times in the head with a hammer, we were told. >> it must tear you apart when you think of her in that room. >> i it's disgusting. >> i hate to think of it because i could just feel more or less the panic that she was in. >>reporter: i"m vanessa's sister find comfort in the heartfelt murals honoring her. they can only imagine when she was killed. >> i felt that he sexually assaulted her in that arms room. >>reporter: they believe eden silence vanessa by killing her. >> no one was there to take care of her. >>reporter: i cecily aguilar was's enough to take robinson into custody finally. but there is a problem. even though robinson was confined and placed as a suspect, he was not under armed guard. so he made his move. >> robinson got out of the barracks and got out of the base. >>reporter: investigators called on cecily aguilar to help. >> you are with aguilar. and she is trying to get robinson to come out of hiding. >> that's correct. >>reporter: investigators told aguilar to call robinson as the couple discussed vanessa's death. and later, maybe feeling the walls close in, robinson texted aguilar links to vanessa's remains being found earlier that day. >> he was covering these news articles, that remains have been found, that they had not been identified as vanessa's. and he said to aguilar they, found pieces, they found pieces. >>reporter: by pieces, investigators were convinced that robinson meant the remains of vanessa by the river. they had a fix on robinson's phone. they moved into arrest him but they would not get the chance. coming up, after vanessa story and all the others, some tough questions for the army. >>reporter: would you say there's a problem with sexual harassment? sexual assault in the military? >> the trends are going the wrong way. that's really tearing at us as an institution. but >>reporter: what will they do about it? >> it needs to be complete enforcement. and the police. >> what do you say when people ask your advice about going into the army? >> i don't know if i could tell my own daughter to go into the army right now. >>reporter: wind "dateline" continues. they moved into arrest him but they would not get the chance. coming up, after vanessa story and all the others, some tough questions for the army. >>reporter: would you say there's a problem with sexual harassment? sexual assault in the military? >> the trends are going the wrong way. that's really tearing at us as an institution. but >>reporter: what will they do about it? >> it needs to be complete enforcement. and the police. >> what do you say when people ask your advice about going into the army? >> i don't know if i could tell my own daughter to go into the army right now. >>reporter: wind "dateline" continues. would make her skin so uncomfortable. now i'm staying ahead of it. dupixent helps heal your skin from within. so, they can have clearer skin and less itch. serious allergic reactions can occur that can be severe. tell your doctor about new or worsening eye problems such as eye pain or vision changes including blurred vision, joint aches and pain, or a parasitic infection. don't change or stop asthma medicines without talking to your doctor. ask your doctor about dupixent. 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(vo) visit mytepezza.com to find a ted eye specialist and to see bridget's before and after photos. the power goes out and we still have wifi to do our homework. and that's a good thing? great in my book! who are you? no power? no problem. introducing storm-ready wifi. now you can stay reliably connected through power outages with unlimited cellular data and up to 4 hours of battery back-up to keep you online. only from xfinity. home of the xfinity 10g network. goli, taste your goals. learn more today. handrea canning:ity army investigators >>reporter: army investigators were sure aaron robinson murdered vanessa guillen. were sure that erin robinson murdered vanessa guillen and how they were closing in on him. >> he's actually seen by an off-duty police officer. and a radio to the local police department. >>reporter: when the officer moved in on robinson, he started to run in the officer gave chase. >> there is this confrontation. and when he goes to apprehend him, robinson takes a gun and shoots himself. >>reporter: right there, in the street, robinson was suddenly dead. >> what's it like when you get that call? that our prime suspect has killed himself? a dramatic conclusion. >> it is. it means that maybe we will never find out why he killed vanessa. it's so open. and it doesn't give us any closure. and it certainly doesn't give the family any closure because they don't know why. >>reporter: so robinson never had to face a judge. but cecily aguilar did. she faces 11 charges, including tampering with evidence, an accessory after the fact. if convicted on all counts, she could be sentenced to 145 years. she has pleaded not guilty. meanwhile, vanessa story became so big that her family was invited to the white house in july 2020. >> we need to change, a positive change. >>reporter: president trump told them that he would look into vanessa's case very powerfully. >> this is a wake up call and it has captivated the attention to the entire military leadership. >> -- i was a soldier and i'm the father of a daughter. i can't begin to understand the pain. i have to look at this, fix this, stem this tide. >> what would you say to the guillen family? if they're watching? >> i am heartbroken. i'm sorry. i'm disappointed. and know that we will do everything we can to make the changes necessary so things like this never happen again. >>reporter: investigators believe that robinson clean the crime scene in less than 45 minutes. but forensic experts only conducted tests two months later, to after vanessa's remains were found. and after robinson killed himself. >>reporter: there's been some criticism that you had a pretty clear idea that specialist robinson was the killer and you let him get away. >> looking at how law enforcement gets a warrant on an individual, it's very challenging how they come to that conclusion, it takes a lot of fact. >> but people say, this is the army, and they couldn't keep an eye on him? >> that's something that has to be looked at. >> we then asked if the former army secretary had looked at the correspondence. >> they say this was botched, -- >> there's a lot of things we can say, where you are in the investigation. that creates frustration for the families. >> and yet they still feel this way. why do you think they feel this way? >> they are upset, andrea. they want answers. we will continue to look at our communications, will be the first to know. but this family is grieving. >>reporter: a big part of the families reef was that vanessa had been sexually harassed. >> do you believe that sexual harassment played a role in vanessa's murder? >> there is no evidence to suggest that vanessa guillen was sexually harassed by specialist robinson. >>reporter: but while her family said that vanessa did not report being sexually harassed, her hierarchies were aware. >> allegations were brought forward about her being sexually rest. >> by a superior? >> i won't get into the specifics, we'll be able to talk more in the future. >> in april 2021, it was revealed that vanessa spoke twice to her chain of command about being sexually harassed by a superior. and no formal action was taken. there was no evidence found that robinson harassed vanessa, but it was determined that he had harassed a different females holder in 2019. the report also concluded that the communication -- the army has disciplined 19 soldiers and officers in connection with vanessa guillen 's case. two others were investigated in relation to the permissive culture found at fort hood. i department of defense report shows that over 18% of active duty women had been sexually harassed and. and over 6% of active duty men. would you say there is a problem with sexual harassment? sexual assault in the military? >> the trends are going the wrong way, the numbers are very high. it's really tearing out this as an institution. >> have you change that culture? >> army is seeing the leaders sitting down with their subordinates and saying, that type of behavior is intolerable, we don't accept it. and if it continues we will hold people accountable. >>reporter: former army captain, melissa bryant, says words need to become actions. >> indeed to be complete enforcement. police and their own. >> what do you say to women about going into the army? >> right now i don't know if i could tell my own daughter to go into the military. i'm not sure that my father would tell me now to go into the military, my father was a vietnam veteran, served 27 years. >>reporter: fort hood seems to impede him eyes the army's long health problems. in 2020, an independent review of fort hood by outside experts found a toxic culture, permissive of sexual harassment and assault at the army base. >> we have a problem. we have to recognize we have a problem. and we've got to fix it. it pains me, that the death of your daughter -- >>reporter: california congresswoman jackie speier chair of the armed services subcommittee on personnel has been trying to highlight these cases for a decade. >> the army would come and say we have zero tolerance for sexual assault and sexual harassment, and they were given a pass. not anymore. >>reporter: she says in a 2019 survey, 120,000 service members that they had been sexually harassed. but less than 1% filed a complaint. when it comes to sexual assault of the 20 plus thousand cases, only about 1% resulted in convictions. >> we are introducing the i am vanessa guillen legislation today. >> she's introduced legislation with strong bipartisan support, the vanessa guillen act, that requires that sexual harassment and sexual harassment assault complaints be investigated by an independent panel. >> why will things be different this time around? >> this legislation creates accountability. there will be independent investigations taking place. and i'm going to guarantee that that kind of investigation in action is taken by the military, and making sure this gets past. >> would you say this is the me too movement of the military? >> i think there's no question that this is the me too movement of military. vanessa will go down in history in saving so many other service members lives. >>reporter: in august 2020, vanessa's casket was taken by horse truong carriage to memorial service at her former high school. the family chose a private burial. though a military funeral was an option. >> we actually declined -- >> really? >> mom didn't want the military casket or anything like that. >> because of how the military handle this? >> right. >> [speaking spanish] >>reporter: vanessa's family hopes her legacy will be about bringing change to the army, bringing voice to so many men and women who have suffered in silence. >> [speaking spanish] that's all for this edition of "dateline", i'm andrea canning, thank you for watching. >> i'm andrea canning and this is dateline. >> what i focus on when i'm working a case, what drives me the most, is the victims. i wanted to speak for them. i want to speak for helene.