National headlines after she was accused of trying to have her now exhusband killed in an alleged murder for fire plot. S she finally takes the stand. And an emotional comeback for celine dion in her first concert since the death of her husband. With one more look at you. Then the powerful encore. Its dat bate pitting the fbi over apple. To be night apple ceo tim cook on why he is refusing to help the feds break into the phone gunman. World news tonight anchor david muir also gets cook to respond to calls by donald trump for an apple boycott. As we sit here you know some of the families of the victims in San Bernardino have now come out in support of the judges order that apple help the fbi unlock that iphone. One family reportedly saying, were angry and confused as to why apple is refusing to do this. What would you say to those families tonight . They have our deepest sympathy. What theyve been through, no one should have to go through. Apple has cooperated with the they came to us and asked us for all the information we had on this phone. And we gave everything that we had. But this case is not about one phone. This case is about the future. What is at stake here is can the government compel apple to write software that we believe would make hundreds of millions of customers vulnerable around the world, including the u. S. . And youd have to write that system in order to unlock that phone . Yes. The only way we know would be to write a piece of software that we view as sort of the software equivalent of cancer. We think its bad news to write. We would never write it. We have never written it. And that is what is at stake here. The fbi though says it believes syed faruk used that phone to communicate with his wife, his accomplice. Do you struggle at all with the possibility there could be information on that phone that could reveal other plots, other San Bernardino attack . David, if we knew a way to get the information on the phone that we havent already given, if we knew a way to do this that would not expose hundreds of millions of other peoples issues, we would obviously do it. I want to get to what the fbi director james comey said. He said its not about a slippery slope, its about 14 people who were slaughtered and many more had their lives ruined. Maybe the phone holds the clue to finding more terrorists, maybe it doesnt. But we cant look the survivors in the eye and ourselves if we dont follow any possible lead out there. Do you understand where hes coming from . I do understand where hes coming from. And this is an incredibly complex issue. But it is about the future. Think about this. If a Court Compels apple to write this piece of software, to place a back door in the iphone, we believe it does put hundreds of millions of customers at reporter we asked tim cook to explain this new system they would have to create to break into the iphone. The pass cord on the front like we all use to get into our iphones. After a certain number of tries it autoerases . What they want is they want us to develop a new operating system that takes out the security precautions, then they want a ability to go through a number of passwords at the speed of a modern computer. A computer would do that . A computer would do that. That is what theyre asking for. We believe that is a very dangerous operating system. You hear that from the republican frontrunner, donald trump what i think you ought to do is boycott apple until such time number. Is that the right route in saying boycott apple . The best thing is americas strongest when we all come together. Together . Is messy sometimes. But this i love democracy. That is who we are vinita nair. I think the best thing to do is to discuss and collaborate and Work Together on whatever the solution may be. Let me ask you this. Youve invite med to apple before. The stories are legendary about new products with black drapery over them, locked doors, secrecy. Any American Company can keep a secret, its apple. To those who might say, why didnt the fbi and apple team up far earlier in one of those secret labs and get this done and no one would have had to know about it . I cant talk about the tactics of the fbi. Theyve chosen what theyve done. Theyve chosen to do this out in the public. For whatever reasons that they have. What we think at this point, given it is out in the public, is that we need to stand tall and stand tall on principle. Theres probably more information about you on your phone than there is in your house. Our intimate conversations, our financial data, our health records. Theyre also loaded with the location of our kids, in many cases. So its not just about privacy, but its also about public safety. If you didnt think this would set a precedent, if you didnt believe this would be a slippery slope, is this something your engineers could do and how quickly could they do it . Weve never done it before so i dont know how long it would take. Would i do it . In a Perfect World where none of the implications that im talking about exist . Yes, we would do it. We would obviously do it. World. In your quiet moments, do you have any concern about you might be able to prevent a terrorist attack by breaking into that phone . David, some things are hard. And some things are both. This is one of those things. In this case, you believe there are some things that just should never be created . Reporter today steve jobs would have turned 61. Cook says not a day goes by that he doesnt think about his iconic predecessor. Have you thought about what he would have done in this situation . Steve always did what he thought was right. And it is so clear to me that he loved what america was founded on so much and would do nothing to put all these customers at risk. Hed be doing the same thing. Reporter tim cook tells us they talked to the fbi early on, giving them advice, he says, on other ways to best get information from that iphone, to plug it in, to back it up to the icloud. Did they do that . Unfortunately, in the days, early days of the investigation, fbi directed the county to reset the icloud password. When that is done, the phone will no longer back up to the cloud. And so i wish they would have contact the us earlier so that that would not have been the case. Very crucial. The white house said this week that the fbis request is limited in scope. Limited in scope, do you agree with that . And have you talked to the president on this . I have not talked to the president. I will talk to the president. Do i think its limited . No. You have talked to the president before on these issues of privacy and security. Yes. Are you disappointed there wasnt more of a dialogue with the administration before this swift action from the Justice Department . Yes. You wish there was more done . Yes. I think there should have been. This filing we found out about the filing from the press. Reporter apple must respond to the court order by friday. Im curious, tim. Did you ever think that youd find yourself at the center of such a crucial National Debate . No. This is not a position that we would like to be in. It is a very uncomfortable position. Something doesnt feel good. And to oppose it on something where we are advocating for civil liberties, which they are supposed to protect, it is incredibly ironic. David, thank you for that exclusive report. In response to our interview tonight a Government Official is telling abc news that it wants apple to be the only one who knows how they develop a new way into their phones, that the fbi doesnt want or need to know that secret. The debate continues. Up next on nightline, the woman at the center of a sensational case takes the stand. Did Dalia Dippolito high to hire a hit man to hill her husband . Celine dion singing all by hers in her first vegas concert since losing her husband. All by myself dont want to be all by myself anymore what if we did for mortgages what the internet did for buying and plane tickets and shoes . You would turn an intimidating process into an easy one. You could get a mortgage on your phone. And if it could be that easy, wouldnt more people buy homes . And wouldnt those buyers need to fill their homes with lamps and blenders and sectional couches with handlathed wooden legs . And wouldnt that mean all sorts of wooden legmaking opportunities for wooden leg makers . And wouldnt those new leg makers own phones from which they could quickly and easily secure mortgages of their own, further stoking demand for necessary Household Goods as our tidal wave of ownership floods the country with new homeowners, who now must own other things and isnt that the power of america itself now shrunk to fit the hands of a child, or, more helpfully, anyway. Thats what we were thinking. Severe ulcerative colitis, the possibility of a flare thinking about what to avoid, where to go. And how to deal with my uc. To me, that was normal. Until i talked to my doctor. She told me that humira helps people like me get uc under and keep it under control when certain havent worked humira can lower fight infections, including tuberculosis. Serious, sometimes and cancers, including lymphoma, have happened; as have blood, liver, and nervous system problems, serious allergic reactions, and new or worsening heart failure. Before treatment, get tested for tb. Tell your doctor if youve certain fungal infections are common, and if youve had tb, prone to infections, or have flulike symptoms or sores. Dont start humira if you have an infection. Raise your expectations. Ask your gastroenterologist about humira. With humira, it is the alleged murder for headlines. Tonight the woman at the center of it, Dalia Dippolito, takes the stand with an unusual defense. Heres abc ace linsey davis. Im positive, like 5,000 sure. Reporter Dalia Dippolito, the woman caught on tape saying she was 5,000 sure she wanted a hit man to hill her husband, was back in court yesterday. Taking the stand for the First Time Since her arrest in 2009 and her conviction in 2011 i have been accused of something that i didnt do. Reporter trying to explain away that incriminating video. She was simply acting. This is supposed to be something you guys are going to put online so you can get publicity . On social media, right. So he can try to get an acting job from it. Reporter dalia says it was part of a plan she hatched with her then husband Michael Dippolito and former lover to get famous. This is acting . Yeah. Reporter prosecutors say that was no act. And allege she promised to pay this undercover cop posing as a hit man to kill her husband of six months. She parked the third space from here. You know, he gets two in the head. Reporter her now exhusband Mike Dippolito said he couldnt wait to see what she said in court. Let me know, ill be sitting in the back with popcorn. Walking on the sidewalk, this doesnt happen very often. No, it doesnt happen at all. Reporter in an exclusive pretrial interview with 20 20 this past December Dalia who is Dalia Dippolito . Understanding, sweet, compassionate. Because of that reporter at the time her newly hired highpowered attorneys wouldnt let her talk about certain parts of the case, particularly those seemingly damning videotapes, because shes now facing a new trial after her first conviction was overturned on a technicality. But yesterday there was no avoiding them. Shes forced to watch that moment weve all seen again and again. 5,000 percent sure. Thats all mohammad told you to say, right . Yes, he told me to say that. 5,000 sure . I needed to project confidence. And yeah. But thats what he told me, to make it look believable. Reporter perhaps the most surreal moment in the courtroom, when the prosecutor plays an audiotape of her trying to explain to her thenhusband mike that she actually didnt pay to have him killed. Please, i need an attorney, can you help me . You said you wanted to have me killed, i heard that. Its not true, that is not true reporter according to her, mike was in on the performance from the beginning. So why, asks the prosecutor, is she trying so hard to convince him . You claim it was all made up, part of a script. How could that not be true . Reporter her attorney, brian claypool, says dalia is the innocent victim ofamehungry Police Department. This case is about a Police Department that tossed her under the bus for purposes of getting fame on a cops tv show. Reporter the nowinfamous moment when police staged a fake crime scene and told Dalia Dippolito her husband was dead. Is your husband michael . Im sorry to tell you, maam, hes been killed. This special edition of cops is filmed on location reporter he says its all part of the plan so be on the Reality Tv Show cops when mohammad came to them with the story about a beautiful woman killed. What the Police Department did is found out shes an attractive woman, in their minds theyre like ching ching ching, this is a perfect skit to get on tape. Reporter not long after filming the exchange between the police and dalia, the Police Posted the video online. Why did you go back to the Police Department and immediately post, on youtube, a video of the staged crime scene of Dalia Dippolito . Well, we posted it as part of our entire plan of publicizing the arrest in this case. You agree with me theres still a pending investigation on Dalia Dippolito and you posted the youtube video, right . Yes. Reporter dalias Attorney Says it adds up to only one conclusion, she was framed. Theres no question about it, that the Boynton BeachPolice Department was dead set on manufacturing a crime here. Reporter abc news senior Legal Correspondent sunny hostin is this a case of entrapment . Do i think that the Police Officers could have done better . Yes. And you certainly dont as the Police Spokesperson upload that video to youtube. Is that a case killer . It isnt. Seems unusual, correct me if im wrong, but for police to lie on camera and create a crime scene, make this elaborate circumstance to say, oh, your husbands dead, when he really isnt. That is unusual but not unheard of. I have to tell you that sting operations happen all the time. Reporter the Boynton BeachPolice Department stands behind their investigation telling abc news the cops show happened to be here at the time of this investigation are were not in the business of producing television. Were in business of saving lives and we believe we did that in this case. Reporter yesterday issuing a statement, we trust in our state attorney to successfully confident we have given his office sufficient evidence to meet the states burden. Still, dalias attorneys filed a motion to dismiss the case based on evidence of what they say is police misconduct. If the case isnt dismissed a new trial is set to start this spring. And theres one person who says he has no doubt dalia is guilty. I am 5,000 sure she tried to kill me. Reporter for nightline im linsey davis in new york. Thanks to linsey davis. You may have noticed sunny hostin providing legal analysis during that report. We would like to welcome her to abc news. Shes joining us as senior Legal Correspondent and analyst. Up next here, celine dion singing all by myself for the First Time Since the death of her husband. Dont want to be all by myself dad, you can just drop me off right here. Oh no, ill take you up to the front of the school. Thats where your friends are. Seriously, its, its really fine. You dont want to be seen with your dad . No, tracy. What [ horn honking ] [ forward collision warning ] bye dad it brakes when you dont. The newly redesigned volkswagen passat. Right now you can get a 1,000 president s day bonus on new 2015 or 2016 passat, jetta, or tiguan models. Red lobsters lobsterfest is back. So come try the largest variety of lobster dishes of the year, like lobster lovers dream or new dueling lobster tails. Its a party on every plate, and youre invited. We live in a pick and choose world. Choose, choose, choose. But at bedtime . Why settle for this . Enter sleep number, and the ultimate sleep number event, going on now. Sleepiq technology tells you how well you slept and what adjustments you can make. You like the bed soft. Hes more hardcore. So your sleep goes from good to great to wow only at a sleep number store, all beds on sale. Right now find our c2 Queen Mattress starting know better sleep with sleep number. Im Hillary Clinton and i approve this message. Her lifes work has been about breaking barriers. And so would her presidency. Which is why, for every american whos not being paid what theyre worth. Whos held back by student debt or a system tilted against them and there are far too many of you she understands that our country cant reach its potential. Unless we all do. Together. Finally, what happened when celine dion took the stage for the First Time Since the death of her husband . Heres abcs Deborah Roberts. Reporter last night celine dion making an emotional return to the stage of the coliseum in las vegas. With one more look at you reporter performing with one more look at you, a poignant tribute to her late angelil. Every time i close my eyes, i felt rene on stage with me. Me. And nothing will ever change that. Reporter its been just a husband to throat cancer. But there was never a question dion would return. My career was in a way his masterpiece. The idea of leaving it unfinished would hurt him terribly. All by myself reporter a heartbreaking moment when dion broke into tears singing all by myself. Pausing to collect herself before powerfully finishing the set. I met dion last spring and though angelil was ill, he joined us on that very stage. Despite it all, encouraging his wife to perform. Sometimes, and i think im used to it, dont feel what you need to feel. Just do it. Go on stage . I did. Because i love him. And i did. Reporter now as a tribute to that love, celine singing once again. For nightline, im Deborah Roberts in new york. Our thanks to Deborah Roberts for that report. Our thanks to you for watching. Tune into gma first thing in the morning. Were online 24 7 on our Nightline Facebook page and at abcnews. Com. Thanks again for watching and good night. Dish nation welcome to dish nation. First, we got to say whats up to atlanta. And filling in for porsha, oh, none other than the legendary jermaine dupree. Weve got to get things started by talking about khloe kardashian. Shell explain why things didnt harden. Hes a basketball player. They were together. They broke up big, big surprise, he cheated on her. She came to this revelation nba. An out. They had a Long Distance relationship. Listen, im not going to try to fool myself into thinking were going to be this monogamous couple. Its geographically undesirable. She sort of gave him a pass. How did he cheat if she gave him a pass. He said, no, no, no, i insist on being monogamous. I want us to have a commitment. The second she was like, well, okay, he cheated on her. She revealed this on cocktails