Right now. Good evening. We now know the husband and wife terrorists who killed 14 people in california last week practiced in plain sight for their deadly assault. Firing at gun ranges as recently as a week ago. And today as we got our first look at the pair together entering the u. S. Last year, we have learned their weapons arsenal was potentially bigger than first thought. And that they were both radicalized long before they struck. Tonight federal authorities are trying to connect the dots to determine whether others may have been involved and whether the duo had even more targets in mind. Stephanie gosk begins our coverage from San Bernardino. Reporter a photo taken at chicagos Ohare Airport shows Tashfeen Malik arriving in the u. S. For the first time in 2014. Syed farook at her side. Both subjects were radicalized and had been for quite sometime. Reporter the fib confirms that the couple practiced shooting skills at l. A. Air firing ranges days before killing 14 and wounding 21. Nbc news has learned that farook was at the magnum range in riverside. As recently as sunday and monday last week. A source closely tied to the range said he was there for hours and was a pretty good shot. The range turned over Surveillance Footage to the fbi in the hours after the attack. Investigators say they are meticulously trying to recreate the shooting inside of the inland regional center. Do you have any sense at this point who was in control during the attack . Did Tashfeen Malik fire the first shot. We have no idea who is in control. Reporter today farooks father made no comment as he entered his home and telling an italian newspaper over the weekend his son was obsessed with israel and shared the same ideology as isis leader albaghdadi. Farooks mother was questioned by the fbi for hours after the rampage. Lawyers for the family say she lived in the same rented house and helped take care of the baby. The mother stayed to herself. I think she stayed upstairs and so she would have been separate and not really known much about what was taking place in the rest of the house. Reporter the house is not large. Just over 1100 squarefeet with two bedrooms. Law enforcement say the garage, which is detached from the building, was turned into a bombmaking factory. The couple was stockpiling ammunition and parts. Enough, the fbi said today, to make 19 pipe bombs. Though not all were assembled. The Justice Department said it is still interested in what farooks mother may have seen or heard. And tonight we are getting our first upcloselook at the inland regional center. There are people who came here today to pick up cars. There is still police tape surrounding this complex, lester. It is still very much an active crime scene. Stephanie. There is late word from authorities that the attack occurred in the very same Conference Room event center where San Bernardino county Health Employees receive training for a workplace shooting just last year. Tonight were getting firsthand accounts of the actual terror inside of that room. From survivors who spoke to Nbc News National Correspondent miguel almaguer. I heard some pop, pop, pop sounds. Reporter it was gunfire that interrupted the good times. We looked at each other and are thinking is it fire crackers and the doors flew open and the gunmen came in. The two were inside of the Conference Center when the masked gunmen suddenly came in. You saw one gunman come in alone. Yes. He was walking toward the middle of the room. It was all very fast. Did it appear as though he was targeting someone . It looked to me more like spraying the room. But in the area where the staff were congregated. Reporter they never saw a second shooter. I saw one gunman came in and we didnt know at that time who it was. Reporter they have since learned he was their colleague. I think we, in the back of our mind, was hoping it was an exercise that someone tried to spring to test our readiness. It seemed endless. It never seemed to stop. It was just constant gunfire. Reporter there were 70 people trapped inside of the large open room. There were exits, but for most no escape. There were three exits to the side of the room. Nobody runs though . Im not sure if people were able to get out. But to stand up and go for the doors, you are in the line of sight of the gunman. Reporter regina was upstairs. Like other colleagues, she ran from the hallway and into the carnage. I saw two dead bodies lying on the floor in a puddle of blood. And i just grabbed both of my coworkers hands and i thought, oh, my god, oh, my god. Reporter the survivors are the lucky ones. But tonight they too are haunted. We are so close. We call each other a family. That is the only way to describe it. Were a family. Reporter miguel almaguer, nbc news, San Bernardino. Absolutely chilling accounts. And as we hear that, federal investigators are trying to piece together the answers to several big questions, including what more might they have been planning. Our justice correspondent Pete Williams is looking into that and the other major areas of concern. Reporter a big question, did anyone else know syed farook and malik were planning some kind of attack . Officials are questioning a former neighbor enrique marquez. Today officials said publicly that five years ago he agreed to buy two assaultstyle rifles for farook. The same two rifles that were eventually used in the San Bernardino shooting. Last week the fbi said marquez was not a suspect. Tonight, after searching his house twice over the weekend, Officials Say they are taking a close look at him. Our major concern, the fbi, atf and the jttf is determining how those firearms and the rifles in particular got from marquez to farook and malik. Reporter Officials Say they dont yet know anything about the couples other plans either. But nbc news has learned that investigators are looking into an account from the management of this 21story Los Angeles Office tower. That someone looking like farook unsuccessfully tried to get inside in the past few weeks. The building overlooks hotels and banks. Also today, the Homeland Security secretary said he will announce a new more flexible Terror Threat warning system. We need to do a better job of informing the public at large at what we are seeing, removing some of the mystery about the global terrorist threat and what we are doing about it and what we are asking the public to do. Reporter so as the fbi assembles pieces of the puzzle from the couples past, it is trying to find out whether anyone else helped provide planning, training or money. Lester. Pete. Thanks. Anxiety and fear over future attacks by islamic extremists is being capitalized on the campaign trail. And tonight donald trump called for a ban on muslims entering the united states. Andrea mitchell has the swift reaction. President obama appealed to americans not to turn against one another and let the war against isis become a war against islam. It is our responsibility to reject religious tests on who we admit into this country. It is our responsibility to reject proposals that muslimamericans should somehow be treated differently. Reporter less than 24 hours later the leading republican candidate did exactly that. Donald trump issued a statement calling for a total and complete shutdown of muslims entering the united states. He says until our country representatives could figure out what is going on. Not just refugees, but tourists, business visitors, all muslims. Supporters tonight in South Carolina embrace it. Ive had too many brothers and sisters lost over there in those two wars to just let them come here free range. Reporter tonight cair, advocating better relations, said donald trump sounds like the leader of a mob, not like the leader of a great nation like ours. He is doing the work of isis. And jeb bush tweeted that donald trump is unhinged. Just as Homeland Security secretary jeh johnson was in an Islamic Center in northern virginia, greeting muslim scout troops and speaking with Muslim Leaders against extremists. We must not force americanmuslims to run and hide and retreat to the shadows. Reporter it is a caution of rhetoric and policy in a nation divided. In San Bernardino ted cruz and trump have been battled for first place in iowa with bombastic rhetoric. We will carpet bomb them into oblivion. I dont know if sand can glow in the dark, but were going to find out. Reporter but trumps latest comments went too far for cruz. That is not my policy. I believe the focus should focus on radical islamic terrorism. And tonight Hillary Clinton just tweeted calling the proposal reprehensible. Prejudice and divisive. Adding that it makes us less safe. Today clinton met with president obama and she opposed discrimination against muslims but her military strategy is tougher than the president she served as secretary of state. We want to go to katy tur who is at Donald Trumps rally about to begin in South Carolina. Youve been on the campaign trail with trump from the beginning. This is really the latest in a string of what many see as inflammatory statements. Im curious how his rhetoric has changed over time and the reaction you are seeing among supporters is. Reporter that is right, lester. This is the latest in a long line of extreme comments coming from the candidate as hes become more hardline on the campaign trail. First, it was that he was open to a muslim data base. Then surveillance muslims. And then closing all mosques. And now he said a ban on all muslims coming into the country and the Campaign Says it includes tourists and even muslimamericans living abroad. And as andrea alluded to, supporters like this and believe this is a wise decision and believe donald trump will keep them safe. It is going to get worse and worse, folks. We can be plit cli correct and stupid and it is going to get worse. They gave him a standing ovation. They think it is a wise move. 60 of Republican Voters according to the latest apology say one of the biggest fears is being a victim of terrorism. Lester . Thank you. When the president addressed the nation last night from the oval office for only the third time in his presidency, he laid out his plan to take on isis. But as our chief Foreign CorrespondentRichard Engel tells us, that plan includes approaches that have already been tried without success. Reporter the president vowed to destroy isis. And outlined a fourpoint strategy. The problem is, three out of the four arent working. First, our military will continue to hunt down terrorist plotters in any country where it is necessary. Reporter the Obama Administration is doing that with targeted drone strikes. A lot of them. Including last month, killing isis beheader jihadi john. Second, well continue to provide training and equipment to tens of thousands of iraqi and Syrian Forces fighting isil on the ground. Reporter the train and assist program has been by any measure, a failure. The u. S. Hasnt found reliable partners and just canceled a program to train Syrian Rebels after they joined al qaeda. Third we are working with friends and allies to stop isils operations. Were working with turkey to seal the border with syria. Reporter another approach tried and failed. Turkey remains the main transit point for isis militants. Fourth, to pursue ceasefires and a political resolution to the syrian war. Reporter that means negotiating a solution with friend and foe alike. Including russia and iran. As the president said, there has been some progress on that front. But the process is slow, the timeline unclear. And the war in syria with over 250,000 dead still has no end in sight. Richard engel is here now. And the president has characterized this as follow this plan or the only other option is allout war. Is that middle ground . There is a middle ground. And people are quite angry that ive been speaking to with what the president is saying. He keeps saying unless you follow this strategy, the alternative is another iraqstyle war with hundreds of thousands of troops deployed for years. But many military officials and counterterrorism officials, say they are many other strategies you could try. Deploying a small number of troops, more air assaults. Cooperating more with iran, russia. It is not just do this plan, keep doing this plan or it is iraq all over again. It is just not the case. Richard engel, thank you. Good to have you here. Still ahead tonight, the shopping rush on guns. Sales spiking once again after the San Bernardino mass shooting. The battle over whether more guns in the hands of citizens makes us safer or puts us in more danger. Also the breakthrough drug credited for helping jimmy carter beat melanoma. Now testing is on the fast track for other forms of cancer too. Well tell you more about it. Gun sales in this country are spiking in the aftermath of the San Bernardino terror attack. In fact, stock in smith and wesson has soared to the highest level in eight years. Peoples concerns about safety and fears of potential new gun laws are often cited as driving factors. And as Kevin Tibbles explains, weve seen this phenomenon time and time again. Reporter as the National Debate rages over gun control, guns are selling. Many worried americans like the hoag family visiting local shops, ready to buy. Maybe a terrorist might not knock down my door but when mayhem starts to happen, i want to be prepared. Reporter they arent alone. Fbi statistics show a marked increase in the number of firearm background checks related to gun sales following each mass shooting in america. A 15 jump following ft. Hood in 2009. A 17 increase after aurora, colorado, in 2012. And a 38. 7 spike after the School Shooting in newtown, connecticut. And coming in january, gun tv. A specialty channel dedicated to firearms. One Study Suggests there could be fewer mass shooting casualties if more people were armed. A small portion of concealed carry could cut down casualties by five to 15 . Reporter but in octobers Oregon College shooting, some people were armed and ten people died. The gun lobby wants to believe more guns are the solution to the problem, if that were true, given there are over 300 million guns in this country, we would be the safest nation in the developed world. The reality is, americans are 20 times more likely to be murdered by a gun than in any other country. Reporter as the argument continues today, the u. S. Supreme court refused to hear a challenge to the chicago suburb of highland parks ban on assault weapons and highcapacity magazines. Kevin tibbles, nbc news, chicago. Were back in a moment with a video released that captured yet another Controversial Police shooting in chicago as the feds make a major announcement about the chicago p. D. The u. S. Justice department has announced it is opening an investigation into the Chicago Police department. This comes on the same day that a video was released showing another chicago Police Shooting which killed 25yearold Ronald Johnson. But unlike the separate deadly shooting of Laquan Mcdonald, charges against police are not being filed over johnsons death. Here is nbcs john yang. Reporter with remarkable detail, prosecutor Anita Alvarez said today she was not charging the Chicago Police officer who shot 25yearold Ronald Johnson in the back as he ran from police in october 2014. The crime cannot be proven beyond a reasonable doubt. Reporter prosecutors say enhanced dashcam video released today with police radio added shows a. 9millimeter gun in johnsons right hand. Police said they wer recovered the gun. Johnsons mother said it was planted. It is a lie. Reporter today attorney general Loretta Lynch launched an investigation into the departments use of force. We are looking to see whether or not the Police Department as a systemic matter has engaged in constitutional violations of policing. Reporter a week ago the city released dashcam video of officer Jason Van Dyke shooting Laquan Mcdonald 16 times. It contradicts Police Reports that mcdonald lunged at van dyke. Van dyke has pleaded not guilty to a murder charge. Chicago mayor rahm emanuel said he opposed a broad inquiry today and today a different tune. We welcome it. And chicago as a city will be better for it. We accept it and we need it. Reporter two shootings caught on camera. The Chicago Police department under federal scrutiny. John yang, nbc news, chicago. When we come back here tonight, it is being called a breakthrough. Can the drug credited for helping jimmy carter beat melanoma work on other kinds of cancer . The warning signs were there. Even before an inmate died in the Santa Clara County main jail take vo next what the woman who sounded the alarm says still needs to change. Janelle take vo and a new journey for a ship that survived pearl harbor and called the bay area home. Next close the news is next. Janelle take vo right finally tonight, how about some good news. The surprise announcement by former president jimmy carter over the weekend that his latest brain scan showed no signs of cancer. It has patients around the country asking about the about the breakthrough drug that hes been taking. Nbcs Gabe Guiterrez has more on the new treatment. Reporter at just 32 years old, Erin Youngerberg was diagnosed with stage three melanoma. It is hard to stay positive all of the time. Reporter but then she began taking a new drug the fda called a breakthrough. Keytruda. It is pretty amazing. You dont want to believe it at first. But with each scan, it gets a little bit easier to believe. Reporter it is the same medicine jimmy carter started taking in august along with radiation. On sunday the 91yearold former president told his Hometown Church about his latest brain scan. When i went this week, they didnt find any cancer at all. Reporter keytruda is part of a new class of drugs that helps the immune system target and kill cancer cells with amazing precision. Fasttracked by the fda last year, the drugs being tested on diseases like lung, colon and Breast Cancer and hodgekins lymphoma. They allow the cancer cells to be seen by the immune system. Reporter it can be expensive. About 150,000 a year. But the side effects are less severe than chemo. No doubt in my mind that it is a real revolution in the treatment of cancer. Reporter while doctors caution it is too early to call this a cure, erin said it saved her life. What the drugs have done give you hope. That were moving forward. Reporter hope for more patients after a president s surprise revelation. Gabe guiterrez, nbc news, atlanta. And hope is a good note for us to close out on tonight. That will do it for us on this monday night. Im lester holt. For all of us at nbc news, thank you for watching and good night. An acknowledgeme nt fromp brass. Right now at 6 00, acknowledgments from the top brass. The sants a clara Sheriffs Office concedes they knew there were problems at the jail. Im janelle wang in forage mathai. Im jessica aguirre. Tonight an admission, the changes at the jail did not come fast enough. In the story only on our station, Damian Trujillo is at the jail. You spoke to the watchdog who long sounded the alarm that something needed to be addressed at the jail. They called the Jail Observer Program for the office of human relations here in Santa Clara County. In her sitdown interview she said there were problems inside the jail before the alleged murder of inmate Michael Tyrese by jail guards. She says there are still problems there today. Almost half the inmates at the Santa Clara County jail suffer from a Mental Illness according to the Sheriffs Office. Kate jones told administrators at the beginning of the year, the jail staff isnt adequately trained to deal with them. Her remarks were in this report. The guards have a tough job and theyve been asked to do things which they are not trained. Reporter then the august beating death of this inmate who suffered from a mental