People see . You were the last person to see people alive. Tonight, a 20 20 investigation, and the only reporter to have spoken to him. A lot of people would say his speech patterns are different because he is aspergers. Now, with an unsolved murder in the familys past, and a new strike just nathan just this week and its not good news for nathan. They want to explore whether or not you sank the boat on purpose. Were done here this evening. Good evening. Im elizabeth vargas. And im david muir. As we come on the air, breaking news, this is a story out of to movies. Rescued at sea after floating for a week. But a major new twist. An Insurance Company is saying the boat sank due to intentional acts. Let us know what you think on facebook and twitter. How linzie janis got this exclusive is a story all in its own. Reporter my name is devin. I work the overnight shift at abc news. On the night of september 26th, i saw that one of the affiliate reporters had tweeted about someone who had been rescued at sea. I sent it around, but, you know, of course we didnt have too many of the details besides that he had been found. He was found in a life raft, with a life jacket on. He was reported to be in good condition. Reporter they sent linzie janis. Linzie janis. Linzie janis has that story for us. Reporter the freighter is due to arrive in boston. When i first heard about the Nathan Carmen story, it looked like an inspiring story of survival. The son rescued off marthas vineyard. Reporter nathan had gone out on this fishing boat with his 54yearold mother linda and never returned. The coast guard combed hundreds of miles of ocean in vain and theyd just given up hope when the call came in. A young man found alone floating on a life raft. Found alive in good condition. Reporter the stunning discovery made in the open ocean by this chinese freighter carrying scrap metal, about 100 miles south of ram point marina in rhode island, where hed set sail. Theyll get the chance to speak with Nathan Carman tuesday night. Nathan, this is u. S. Coast guard boston. I need to understand what happened. Reporter yeah, we all do. But so far, the only explanation, this short radio call from the coast guard to nathan aboard that freighter. Mom and i, two people. Myself and my mom were fishing at block canyon. And there was a funny noise in the engine compartment. When i saw the life raft, i did not see my mom. Have you found her . No, we have not been able to find her yet. Reporter the next day, nathan arrives in boston. The questions waiting for him at the dock. The most important question is, how did you survive and not your mother . Reporter when we first see him, he shows little emotion. His 63 frame awkwardly appareled in the white crew suit he was given after his rescue. That night, nathan returns to his home in Rural Vermont and makes his first public statement. I would just like to thank the public for their prayers and for their concern for both my mother and for myself. Emotionally, ive been through a huge amount and my request is just to be allowed to mourn naturally. Reporter it seems thats all he has to say. But then nathan decides to grant us an exclusive interview. He instructs us to meet him on this bench. He seems anxious, traumatized. Im not sure how best to say this. Reporter worried he wont look or sound good on camera. Oh, lord, may you help us to reporter he even prays about it. Help me to accurately and effectively express what i have been through. Reporter theres a reason nathan doesnt speak in the tongues of angels. He has been diagnosed with aspergers syndrome, which is on the autism spectrum, associated with social awkwardness and flat, measured speech patterns. Lets begin, if we could, with the fishing trip. Our conversation will last into the night but it ends up a fragmented account with plenty of blank spaces. Im not going to go into that now. Im not going to answer that. Im not going to go there. Reporter but nathan is able to provide more details about that ordeal at sea. My mom and i fished very frequently together. Thats the primary thing we did to spend time with one another. We fished probably every other week. Reporter despite his humble appearance, it turns out nathan is actually from a wealthy new england family. The first of many surprises. His mom linda, a nurse who worked with autism patients, didnt even like to eat fish. But she loved catching them with nathan. In this facebook posting, she said, there was no better way to connect. Nathan had purchased this nathan had purchased this 31foot fishing boat, named the chicken pox, after seeing it advertised online. He says that on september 17th, he and his mom set out for that fateful trip just before midnight. These fishing trips, you would often leave, what, at night or in the early hours of the morning . Thats correct. We met at the marina in rhode island, got all of our gear on board, pushed off from the dock. Reporter nathan wanted that night to be different. He says that instead of the usual trip of about 20 miles to block island for striped bass, he decided to go deep sea tuna fishing, to that area called block canyon. Thats much farther offshore. Thats offshore fishing. Reporter it takes all night to get there. The sea bed here drops from a few hundred feet below the surface to 1,000 feet or deeper. A perfect spot for those giant tuna they were after. I have experience boating. I have experience fishing. I did not have experience offshore fishing. Reporter but nathan was comfortable making the trip because, he says, the seas were calm after a smooth cruise through the night. We arrived just as the sun was rising. Reporter nathan says the new day was perfect. They set their lines and fish for tuna, all by themselves. They have life vests onboard, but werent wearing them. Hours passed. It was midday when he says the trouble started. So what happened . What went wrong . I heard a noise. Reporter a funny noise coming from the engine. The engine sounded different. I looked in the hatch where the engine was, i observed there was water. Quite a bit of water. The belt on the engine was picking up water and kind of spinning it. Reporter what did you think . I knew there was a serious problem. But i didnt think we were sinking. I thought i was going to diagnose the problem and that we were going to go back to shore. Reporter he says he closed the hatch and shut off the engine. He says he told his mother to gather the fishing lines in the rear while he says he brought the ditch bags full of safety gear up to the front. But he says to his shock, in no time the boat was under water. I was walking on the deck. It was there. And then it wasnt. Reporter any sign of your mother at this point . No. Not at that point. Reporter he claims he was totally disoriented. Doesnt remember hearing his mother or seeing her. The life raft was designed to inflate automatically. Nathan says he swam to it. I got onboard the life raft and was looking around and i was calling out to my mom. I did not see or hear my mom. I was blowing the whistle with three loud, short bursts, which is a distress signal. Reporter so if she had been on the surface of the water you feel like you wouldve been able to see her . I assumed that if she had been on the surface and conscious that she wouldve been calling out to me and i wouldve been able to find her. But i didnt know why that hadnt happened. Reporter now, by his account, he was all alone in a kind of floating tent. A tiny speck of orange in a vast grey sea. As that night fell, he was drifting in the darkness. Like tom hanks in castaway, nathan says he spent days alone out in the open water until just like the movie, the freighter that saved nathan, aptly named the orient lucky, was docked when we intercepted it later that week. Theyd recorded this remarkable footage of the rescue. Look here, that little figure is nathan, clinging to a life preserver, clinging to life, then jumping into the churning seas. As the ship struggles to stay close enough to grab him. We could see he was very tired. Exhausted. He rested for a while clinging on to the ladder. Our crew helped for him to get onboard our ship. I was no longer lost and thats when i allowed myself to feel relief. Reporter what was going through your mind . Im safe. Reporter its a compelling, heartstringtugging story of loss and survival. That i love my mother, present tense, i love my mother. Reporter but is it also something more . Police want to know, what role, if any, Nathan Carmen played in his mothers disappearance. Wait a second. Was this just an accident . Reporter is his story really the whole story . As more details emerge, the portrait of the young fisherman takes on a darker hue. It paints a very troubling picture as to what was nathans intent. Ople in here. Their training is developed by the same company who designed, engineered, and built the cars. Theyve got the parts, tools, and knowhow to help keep your ford running strong. 35,000 specialists all across america. No one knows your ford better than ford. And ford service. Right now, get the works a Synthetic Blend Oil change, tire rotation, Brake Inspection and more for 29. 95 or less. Pretty little love birdsine bsing to me they dont got a care, just a melody, yeah, yeah burts bees lipstick. 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Reporter Nathan Carman was found floating on a life raft in the ocean. Reporter two members of the carman family went out to sea. Only one came back. So why are people so suspicious about what exactly happened to nathans mother linda . Now officials are investigating just how the 31foot boat sank. Reporter that suspicion deepens as we learn that the motherson relationship could be as choppy as the north atlantic. Well, i think anyone who has a child that has autism or aspergers, its difficult. There were conflicts on occasion, but he considered her his best friend. Reporter in addition to any personal friction, investigators see a possible financial incentive for foul play. Is nathan due to get a huge windfall . Is he due to get all of his mothers money . Thats my understanding. Reporter millions of dollars . Yes. Think its around 7 to 8 million. Reporter thats why a phalanx of investigators local police, the coast guard, even the fbi are taking a hard look at signs of possible criminal activity on that doomed boat. And so are we. This is ram point marina in rhode island, where nathan and linda set sail that night in september. Welcome aboard. Come on in. Reporter captain Dave Mccormick runs irish jig charters and was out fishing the day nathan and his mother set out on that sevenhour trip to block canyon. Captain dave considers it highly unusual for a mother and son to fish alone for tuna. Those fish can weigh hundreds of pounds. Theres usually a crew of four, and its usually all experienced guys. Reporter usually a crew of four experienced fishermen. Usually. You know, to be smart about things. Reporter on top of that, captain dave says a 31foot boat like the chicken pox would be too small a vessel for even the most experienced fisherman. And remember, nathan had never done this before. First time youre taking your boat that far offshore . Thats correct. Reporter captain dave is also puzzled by nathans actions after he says he reached block canyon and realized the boat was taking on water. There was a functioning alert system onboard, but nathan never used it. How long does it take to activate or make a mayday call . Its just a matter of seconds. You just flip the switch, and its activated if its a manual type. Reporter the coast guard said there was no mayday call. Did you have a radio on the boat . I had a radio, and there was also an emergency positionindicating radio beacon. I didnt know that we were sinking. I knew that we had a problem, but i didnt know that we were sinking until we sank. If you look at nathans behavior, if you take all of those things collectively together, it paints a very troubling picture as to what was nathans intent and what actually did happen to his mother. Hello, this is Nathan Carman. Reporter and what to make of nathans seemingly odd behavior after he was rescued . Just listen to his call with the coast guard. So i got to the life raft after i got my bearings, and i was whistling and calling and looking around and i didnt see her. Reporter nathans affect is as flat as pavement as he recounts the tragic loss of his mother, asking about her seemingly as an afterthought. When i saw the life raft, i did not see my mom. Have you found her . Reporter but wait before you judge. Psychologist dr. Rebecca sachs says people with aspergers often speak without emotion, and order their thoughts in a way others might find unusual. Picking out what is the most important piece of information is often really, really difficult. Theyll sort of give information in a linear fashion. Reporter so youre saying that its not necessarily unusual that he didnt lead with, my mother is missing . Correct. Reporter sachs also says people with aspergers affects how he interacts with others, and can lead to misunderstanding. Take what happened at this donald trump rally in New Hampshire, which nathan attended just weeks before his mothers disappearance. Nathan who told us hes a big trump supporter was removed from the rally after the man who took this photo reported him to security because he said he was uncomfortable with nathans demeanor. And now, watch this odd moment during our interview when nathan reveals his mother needed coaxing to go on that fishing trip at all. She was concerned about safety . Thats correct. It was not an argument. I was kind of pestering my mom. She had always been kind of skittish were stopping right here with that question. Reporter oh. Okay. Out of nowhere . Stopping right there. Reporter and its like, what happened . I sometimes talk about this need to control things. Or thinking they know how to guide a situation or guide a conversation. I think thats just an impression that comes off. Reporter so maybe some of that seemingly defensive or suspicious behavior can be explained by nathans aspergers. During our interview, its hard to get a full picture of him, in part because hes on edge after a crowd of media gathered, hoping to get to speak with him. As he got back in his truck, i head back to new york, haunted by one question. Just who is Nathan Carman anyway . Its time to dig deeper for an answer. Time to explore some dark and troubling secrets of nathans past. This wasnt the first time he was in the news. Patrol officers have been briefed to keep a lookout for Nathan Carman. Reporter when 20 20 continues. Something bigger. Here. And something. Smaller. Juicy. Lettucey. Oniony. Cheesy. Iconic big mac®. Now in three sizes, for a limited time only. Ba da ba ba ba listen, sugar, were lettin you go. Its that splenda naturals gal, isnt it . 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But so much was left unsaid about nathans past, about how he survived, and as the days go by, the swells of suspicion are bearing down on him like a noreaster. Youve got to presume that hes thinking, im going to tell my story, im going to put it out there, its going to end this. Thats not what happened. Reporter and then, surprise. 193 miles. Nathan invites us back to vermont for a second interview. Were hoping this time hell fill in some blanks. When we arrive at his home hi, nathan, how are you . Nathan seems as adrift as he was out in the ocean. I was lost at sea, my mom died. What would be great, to have people embracing you, saying we are glad you are home, we are glad you are alive and also helping me to deal with my moms death. It hasnt been that. Reporter nathan says he was counting on support from lindas three sisters, his aunts. Instead, theres been a stony silence. I havent received any calls. Reporter not from a single one of them . Thats correct. It makes me feel like i have no family. I want to have family, i want them to be my family. Reporter nathans aunts dont want to speak with us either. Its a terribly, terribly upsetting and difficult time. Their focus is not on relationships, its on getting answers to questions. This barn may be from well before 1850, i dont know. Reporter wow. Despite whispers he might have killed his mother for millions of dollars, nathan is hardly living the lush life up here. He spends days his renovating this house, hoping to flip it by the springtime. So far the only interested parties to come knocking have been the police, searching for evidence of a crime on the high seas. The 22yearolds demeanor was strange. Reporter driving around with nathan, he seems unfazed by the police attention. Had your mom come up to visit you here . Yes we, she drove up to the area frequently. And we saw each other. Reporter he says he called us back to set the record straight because so much of what hes seen on the news has been unfair. Right this way. Reporter this is not easy for nathan. I am not someone who understands relationships or who is good at talking about emotions. Reporter but hes willing to try. As he opens up a bit, its clear, hes had a hard life, the loneliness hes feeling now is nothing new. In fact, its been a lifelong companion. Nathan grew up about 100 miles south of here, in middletown connecticut, a suburb of hartford. An only child from a broken home. His parents divorced when he was very young and for most of that time, his mother linda was everything to him. What was she like . She was a good person, a warm person. We did have a challenging relationship at one point in my life but she was the only family who i really had and now i dont have her and thats a tremendous loss. Reporter you feel alone . Yes, when i had her i didnt feel alone. Considering she was the most important person in his life the most important and fundamental question of course is, would he really have wanted to kill her . Reporter another port in the storm, this man. His grandfather, lindas dad, John Chakalos. A multimillionaire real estate and nursing home developer. He was like a father to me. And i know i was like a son to him. Reporter they ate dinner together regularly at grandpas house and there were even numerous take your grandson to work experiences when chakalos carted young nathan to business meetings with his associate pat goggins. I got the feeling that john had a very Good Relationship with him and was trying to cultivate that. Nathan was as introverted as john was extroverted. Reporter not surprisingly, that introverted personality trait didnt go over big at middletown high school, where classmates recall him being mocked. But he did have one close friend. A beautiful white horse named cruise. Lucky you, having your own horse. Yes, i was fortunate in that regard and i was able to really form a strong bond emotionally. Reporter but when nathan was 17, cruise died and nathans fragile world fell apart. Shortly after cruise died, you ran away from home. Police are asking you for your help, theyre trying to find a missing teenager from middletown. Patrol officers have all been briefed to keep a lookout for Nathan Carman. Reporter nathan had been spotted taking a bus. Teams of searchers looked for him for days. Running away from home is something that i felt i had to do at the time. I dont fully understand it or comprehend that sitting here now. Reporter he was eventually found nearly 600 miles away in rural virginia. When he returned home, nathan was reportedly hospitalized briefly for Mental Health issues. When you returned home after you had run away, when you were found . Yeah, that gets into my personal health records, which i am not going to disclose or discuss. Reporter did things get better or did they get worse . I cant answer that question and were done with that before i turned 18. Reporter nathan was released and for a time, whatever storm was raging inside of him subsided. But for how long . Reporter coming up, the holidays turn bloody as grandpa chakalos is gunned down just before christmas. And the police want to know, did his quiet, beloved grandson pull the trigger . Yes, nathan was a suspect in the murder of his grandfather. Reporter stay with us. Baby. Hone, singsongy fat guy in a little coat. That rug really tied the room together. Any questions . Bueller . Bueller . Thats the unlimited effect. Stream your entertainment and more with unlimited data when you switch to at t wireless and have directv. Plus, get the amazing new iphone 7 on us. What if instead of waiting weeks for your tax refund . You can get an advance on that refund. [zombie] an advance on my tax refund, i could really use that. 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Reporter christmas in new england, and people come from miles around to see this elaborate light display. John chakalos puts up at one of his many properties, but the holiday spirit ends abruptly on the violent night of december 20th, 2013, when the real estate millionaire is found shot to death in his connecticut home. Authorities say executionstyle. One of his daughters had gone to check on him, and found him in his bed with what looked to be gunshot wounds to his head and back. Police are now calling the shooting death of an 87yearold man a homicide. Reporter who would want John Chakalos dead . Its a very good question. Reporter at first police wonder, could it have been his daughter linda . There are reports of a big fight over the family fortune which got violent, linda punching and kicking her father. In the investigation, it has to be a relevant question to ask, is that incident connected to what happened to him . Reporter but a Lie Detector Test clears linda. So, logically, cops focus on the last person known to see chakalos alive, none other than his beloved grandson. Nathan had no obvious motive to gun down his granddad, but he had opportunity. The two had dinner together earlier that evening but police say nathans whereabouts later that night are unaccounted for. The authorities wonder, could that have been the time when he committed a murder . Reporter and, according to this search warrant, there is a litany of other circumstantial evidence. It says nathan discarded both the hard drive of his computer and the gps unit used on the morning of december 20th, 2013, that he had recently bought a. 308 caliber rifle, the same caliber weapon used in the homicide of john chakolas. Coincidentally, neither nathans rifle nor the murder weapon were ever found. Is it fair to say he was your prime suspect . Yes, that is fair to say. He was definitely our prime suspect. Reporter police say that after John Chakalos murder, lindas sisters were afraid enough to hire Armed Security to protect them in their homes. Were they afraid of nathan . John chakalos was murdered in cold blood in his bed, in his home. It would be irrational not to feel some fear as a result of that. Reporter with regard to the murder of nathans grandfather, isnt the circumstantial evidence there strong . Well, if it were there and it were strong, they wouldve arrested him. Reporter that search warrant has a list a mile long of things that make nathan look suspicious. You cant arrest anybody in america on mere suspicion. You have to have probable cause. Reporter is there any truth to any of those allegations . No, there was not any truth to any of the allegations. Reporter nathan adamantly insists hes innocent. He says when the police came to interview him, he never tried to hide anything. If they had asked me, nathan, can we look at your hard drive, or, nathan, can we have your gps, at that time when they were in my apartment, my answer would have been, sure, gladly. You can take it. But they didnt. Reporter do you think the police have picked on you . I think the police saw me as the lowest hanging fruit after my grandfather died because they saw that i had been diagnosed with aspergers. Theres an element here of prejudice against nathan, because of his disability, because when the police talked to him, they immediately become suspicious because of his odd manner. Reporter in fact, experts tell us people on the autism spectrum are more likely to be victims of crime than perpetrators. My understanding is that if you lie to the police and they can prove that you lied to them, they can arrest you for that, and they havent done so. Nathan remains a suspect in the murder of his grandfather. The investigation is actually very active at the moment, and ongoing. Reporter just last month, Law Enforcement went back to the scene of the crime. Hoping this helps find them more answers. Reporter the fbi also conducted a separate search elsewhere. The fbi and other agencies searching property owned by John Chakalos. Reporter over a dozen agents wearing hazmat suits scoured this abandoned New Hampshire property owned by the family, continuing the quest for the missing murder weapon. But its not just the investigation into his grandfathers murder hanging over nathans head. The inquiry into his mothers disappearance at sea is also steaming ahead. Suspicious new details have emerged, allegations of sabotage. Whatever he was doing was wrong. Reporter allegations nathan would rather not discuss. Im just asking you to defend yourself against these people who are saying that you did something to your boat that would make it sink. Were done for this evening, period. Were done here. Reporter were not trying to make you uncomfortable. Why is nathan so agitated . Were done here. Reporter it is his condition . The suspicions about him . Or a guilty conscience . H times. Because shes your best friend. And your true love. The ever us twostone diamond collection. Now available in earrings, bracelets rings and necklaces. One diamond for your best friend, one diamond for your true love. For the one woman. Whos both. Ever us. Available at jared, kay and zales. Youreno, no, nois up she came on to you . I was walking down the street and from the other side, hey hey who is that . She just. She cat called you . No. He was just friends. He was friends with my pavlik. And thats a different story. Oh, you stole her from her boyfriend . And since then im suffering. They lived happily ever after for how many years . 15 . 130. No, contenders. Im out of data again i cant work out without my music you need to switch to sprint. I got unlimited data, talk and text for 50 bucks a month and you get 300 off a Samsung Galaxy s7 edge. I didnt even have to wait on my tax refund. I heard 5 gigs of data is all you need. Hows that working out for you . vo get sprints unlimited plan for 50 a month. Plus, get the Samsung Galaxy s7 edge and save 300. Looks like im not the only one who switched. For people with hearing loss, vo switch to sprint. Visit sprintrelay. Com. Reporter no matter what Nathan Carman says, the fog of suspicion isnt lifting. Can you understand what people see . You were the last person to see two people alive. You are either incredibly unlucky, the most unlucky guy, or you had something to do with those two deaths. What do you say to that . I say there is no relationship between my having been the last person other than the killer to have seen my grandfather alive and my having been on the boat with my mother when it sank. I did not kill my grandfather. I did not cause my mothers death. And i want people to know that. Reporter nathan may sound sincere. But is he credible . The story makes no sense. Supposedly, the boat springs a leak, and no one can say, hey mom, you want to join me on the raft . There are too many questions without answers and too many answers without justice. Reporter when we ask nathan what happened to cause the boat to sink, he says he simply doesnt know. I am not a Diesel Engine mechanic. Thats the most basic way that i can respond to it. Reporter but the police arent buying that. They executed a search warrant of nathans home, looking for evidence of reckless endangerment. Noting that nathan had been seen doing repairs on the boat that potentially rendered it unsafe. Boat owner mike iozzi bumped into nathan on the dock just hours before his fishing trip and told police that he saw nathan doing something highly suspicious. It kind of caught my eye when i saw him leaning over the back and drilling two holes in the transom of the boat. Reporter drilling holes . Mike was dumbfounded. He says nathan told him that he was removing stabilization devices like these, something called trim tabs. Mike says that made no sense. You dont have to drill a hole to take the trim tabs off. Why would you drill a hole in the boat . Whatever he was doing was wrong. I am not sure how i can respond other than saying, he says one thing and i say this is what actually happened. Reporter nathan categorically denies any suggestion that he sabotaged the boat. He admits removing the trim tabs, but claims he patched the holes properly with marine putty. When we press him, he reaches a breaking point. All i can say is what happened. If other people want to reporter im just asking you to defend yourself against these people who are saying that you did something to your boat that would make it sink. Thats not true. Reporter okay. Another thing thats happened since we last got together. The police searched your moms home. Did you know anything about that . Yeah, were done for this evening, period. Were done here. Reporter were not trying to make you uncomfortable. Were trying to give you an opportunity to answer some of these allegations. Were done here this evening. When someone gets up from an interview, calls it off, typically you think, person cant deal with the heat. Questions are too tough. But maybe theres another explanation here. And that is his medical condition. A person with autism may not understand exactly all the social rules of what may happen. How maybe their instinct to react may not always be the most appropriate. Reporter sure enough, about 20 minutes later, nathan is ready to sit back down as we probe one final, highly curious part of his story. Namely, what exactly happened during those seven days on that life raft . Most people would panic, nathan. Most people would think, im going to die out here. And the way i handled that was to focus on what i had to do in order to survive. Reporter nathan says he had fresh water packets in his survival bags as well as kits to allow him to drink sea water. He also had food bars. He says he allowed himself only one each day. Here we go, wilson. You dont have to worry about anything. Reporter in castaway, tom hanks talks to a volleyball he names wilson. Wilson reporter nathan says he talked with god. I prayed in the morning. And i prayed in the evening. Reporter that made you feel less alone. That was very comforting. Reporter of course, those prayers were answered when the orient lucky appeared. And after a week at sea, the miracle was complete. Or was it . So if you were 100 miles offshore, youd want a bigger life raft. A better life raft . A better life raft, yeah. Reporter jim oconner sells life rafts for a living. And he says nathans account just doesnt hold water. Nathan says he was in that life raft for about a week. Does that sound survivable to you . Barely. It happens. It has happened. But the life raft was not the type of life raft that somebody would normally survive a week in the conditions he was in. Reporter nathan says the seas were calm sometimes. And then very rough. With waves as high as 13 feet. He says he would close the door and ride it out. I expected the life raft to flip over at some point, just because youre in a small life raft in big seas. Reporter but oconner says the type of raft nathan was in would have tumbled so violently he would likely have broken bones. He was in really good shape. For somebody who was in 13foot seas in a small life raft, he was in remarkably good shape. Reporter whats the talk in your industry . What do people think . That he might have not been out there for seven days. That he might have been in that life raft for a day or two. If the boat didnt sink on day one, and sunk, say, on day four. Or day seven, that fundamentally changes the story. Reporter could nathan have drilled and filled those holes, sailed into open water, killed his mother, and then waited to scuttle the chicken pox until he saw the orient lucky coming over the horizon . He could have thrown her overboard, stayed on the boat for a while. We dont know exactly when that boat sank. Reporter its easy to speculate about foul play. But proving it wont be smooth sailing. The wreck of the chicken pox may be 1,000 feet under water and without the evidence, its hard to see anything more than a circumstantial case against nathan. Well, i say, produce the evidence. If you dont have the evidence, please keep your mouth shut, because youre ruining someones life. Reporter but wait. New information tonight in the case of a mother son fishing trip. Reporter just this week, one group of investigators says they have come to a conclusion. Nathan puts his mother to rest, but not the nagging questions. Have police told you anything about the status of the investigation . 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Im vern, the orange money retirement rabbit, from voya. Riiight. And that means. . Im the money you save for retirement. I help you get organized so your money could multiply. See . Got it. Whos he . Hes green money for spending today. You know, paying bills, maybe a little online shopping. Makes it easy to tell you apart. That, and i am better looking. I heard that. When its time to get organized for retirement, its time to get voya. Reporter a private service held today to remember linda carman. Reporter six weeks after she was lost at sea, linda carmans body still hasnt been recovered. Yet her son nathan organizes a memorial for her in downtown hartford, connecticut. Nathan carries flowers himself to the sparsely attended service. The media outnumber the mourners. How have you been these last several weeks . Its been very difficult. How was the service today, nathan . The whole family was invited, im glad that many of my moms friends chose to attend. Reporter but conspicuously absent from the service, nathans three aunts. Why didnt lindas sisters attend the Memorial Service that nathan organized . They didnt feel it appropriate to have a Memorial Service when we dont know what happened. Reporter are lindas sisters afraid of nathan right now . Lindas sisters are afraid, as we all should be. There is a killer out there. I wish very much that my whole family could have come together to pray for my mom. I wish desperately that my mom was rescued. I hope that she will be found. Now im going to drive off. What about your grandfather. I need to close my door. Sorry, nathan. Reporter in the midst of all this family dysfunction and the ongoing criminal investigation the questions hang in the wintry new england air. If nathan did plan to kill his mother, why would he have risked his life in that raft, since he had no way of knowing hed be rescued . Or was the multimillion dollar fortune hes now set to inherit from his mother motive enough to risk it . Until these cases are solved, and proven that he didnt have some involvement, people are going to believe hes the only game in town, hes the right guy. Reporter but just this week, shocking headlines. An insurance investigation blames nathan directly. The Insurance Company filed papers in u. S. District court, claiming nathan made incomplete improper and faulty repairs to the boat. Reporter the company wont pay his claim because it finds what nathan did was intentional, specifically removing part of the boats structure and heading to sea with four inadequately filled holes. The Insurance Company believes that the boat sank because of nathans actions. Its very troubling. Reporter small points out that investigators did not make a finding on what happened to linda. So far, theres been no response from nathan in court. We wanted to ask him not only about the investigation of the fishing boat but also about that recent fbi search of his grandfathers property. So weve been trying to get a hold of nathan. He hasnt answered my texts, my voicemails. Im going to give him one last call. The number you have called is no longer in service. Reporter he disconnected his phone. Nathan has disconnected his phone. Sealed in his fortress of solitude, cut off forever from the two people who loved him most, Nathan Carman may long be remembered as we first saw him. A riddle wrapped in a mystery inside a white crew suit. Is he a cunning and remorseless killer, capable of killing his closest family members . Or just a lonely, tragic figure who, like the rest of us, only wants to be understood . Tonight, even after all our questions, the answers seem as remote and murky as the bottom of the ocean. Nathan seeming to have cut off contact with everyone. So, our question for you at home. 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