>> Tonight. Breaking news. Former Vice President Mike Pence appearing before Trump grand jury and testify all day before the panel in Washington investigating former President Trump's efforts to overturn the 2020 election one day after a federal appeals court denied Mister Trump's last-ditch effort to stop at what we know. The suspect to the massive leak of secret U.S. documents appearing before a federal judge amid fears he could be a flight risk. Plus the new details in his home arsenal and the evidence prosecutors said he tried to destroy the WNBA star Brittney Griner speaking out for the first time since her release from a Russian jail. How she says she stayed strong and her advice to Americans still being held. We're growing flood emergency. The Mississippi River cresting, but many towns not out of the clear barge. Traffic halted a train derailed cars spilling into the river with the worst yet to come. Tucker Carlson breaking his silence after his dismissal by FOX News. The new findings about a diabetes drug that could be a game-changer for weight loss. The changing face of Hollywood. How production is being transformed by artificial intelligence. >> NBC Nightly News with Lester Holt. >> Good evening and welcome. We begin tonight with breaking news. Sources familiar with the matter tell NBC News that former Vice President Mike Pence appeared before a federal grand jury this afternoon as part of the special counsel investigation in the former President Trump's attempts to overturn his 2020 election defeat. It's believed Pence has direct knowledge of Mister Trump's efforts to block certification of the 2020 election Pence's testimony legally pitting him against the man who could very well be a rival for the 2024 Republican nomination. It one of 2 major stories we're following concerning Mister Trump's legal problems. Laura Jarrett joins me now with details. Laura, this is testimony that the Trump team had been trying to block. >> Yes, Lester, a dramatic development today. The former vice president testifying for hours in front of that grand jury in Washington. We saw his car when in around 09:00AM and didn't leave until 4.30. prosecutors now able to secure that could be pivotal testimony. The conversations Pence had with former President Trump leading up to January 6 as we know they are particularly focused on Trump's efforts to block the certification of the election. And Pence appearance came less than a day after a federal appeals court rejected Mister Trump's bid to block this very testimony. >> We're also watching this civil lawsuit. Jean Carroll alleges that the former president tried to sexually assault her. She was under cross-examination today. It got. >> Very heated. Lester, Mister Trump's defense team suggesting, Carol, is lying about this alleged assault that she was motivated by her political opposition to Mister Trump and that she tried to cash in by raising this alleged incident for the first time in her book, attorney Joe Tacopina pressed why didn't she come forward earlier screen during the alleged attack? What she says happened in a department store dressing room by this point, Carol is sobbing saying, quote, he raped me whether I screamed or not. It grew so tense. The judge interjected scolding Tacopina for being argumentative. All right, Laura, thank you for that. >> Tonight, prosecutors are trying to keep the young airman suspected of orchestrating that massive leak of U.S. intelligence secrets behind bars as new evidence was revealed back Jack to share is alleged attempt to conceal his actions. Here's Peter Alexander. >> Tonight, former Massachusetts Air National Guardsman Jack to share his fate is in the hands of a judge with federal prosecutors urging the court keep him behind bars until trial saying he's a flight risk and may still have classified material that could have tremendous value to hostile nation states. The judge opting to consider arguments and issue a ruling later in their new filing on to Sheryl who's charged with leaking highly classified military documents online. Prosecutors allege the 21 year-old took steps to conceal his actions. Authorities finding a tablet, a laptop and an X box gaming console smashed in a dumpster and to share his home. Prosecutors allege he has a troubling history of making racist and violent comments on social media last November. Writing if I had my way, I'd kill a expletive ton of people into shares bedrooms. Prosecutors say they found an arsenal of weapons including handguns, rifles and AK style high capacity weapon and a gas mask to share is accused of leaking damaging information about China. The war in Ukraine as well as documents that reveal how the U.S. is gathering intelligence on its allies. The U.S. is under pressure to determine why an air man and tech support had access to some of the nation's top secrets. >> The sad reality is that it seems like our Department of Defense has less of a rigorous insider threat and vetting process program in place that even corporate America does. >> To Sharon has not yet entered a plea. His lawyer calling a 21 year-old kid who lives in his home town and would stay with his father if released. For its part. The Air Force is now suspended. 2 commanders from to share is intelligence unit Pentagon investigation Luster. Peter Alexander, thank you. For the first time since she was released from a Russian jail, WNBA star Brittney Griner spoke extensively about her confinement and how she got through it. We get more now from Andrea Mitchell. >> The 6 foot 9 WNBA superstar getting emotional sharing how she stayed strong for 10 grueling months in a Russian jail. You know, I'm no stranger to. >> Hard times. See you cry, but you may be just digging deep. Honestly, you know, you're going to be faced with adversity these throughout your life. This is a pretty big one. I just kind of relied on my hard work and never giving up when I did lose my home. Looking at photos of my family that brought the whole back. >> The seven-time All-Star and two-time Olympic gold medalist rejoining the Phoenix Mercury after more than a year away from professional basketball. The saying she won't play overseas again unless it's for the Olympics. That will be the only time I would I would leave the U.S. oil. And that's just to represent the USA Griner. A new team unveiling a mural in support of other Americans still being held in places like Russia and Iran and sending them this message. Stay strong. >> Keep fighting. Don't give up. You know, it hurts. It hurts because no one should be in those conditions. >> Major newspapers are running full-page ad calling for the White House to step up its efforts to bring home American Wall Street Journal reporter Evan Gershkovich with Russia again today denying an embassy request to visit him next week. >> The Biden administration is now sanctioning security agencies and Russia and Iran for not releasing Americans, but those agencies have been sanctioned before to little effect. >> Western OK, Andrea, thank you. That flooding emergency in the Midwest is far from over tonight. The Mississippi River continuing to rise in many towns halting barge traffic in a part of a major shipping artery. Maggie Vesta is watching us now from Iowa. >> With flood waters rising and the danger zone. Deepening warnings about the slow motion disaster taking shape along the Mississippi River's banks sparking new longer term fears if you have several cars in the water. >> Tonight, a freight train derailing along the Mississippi in DeSoto, Wisconsin. At least 2 cars falling into the water. The cause under investigation. Meanwhile, the USDA halting barge traffic across much of the river. More than 20 flood gauge is showing major flooding from Minneapolis to Burlington, Iowa. Some cities slated to remain at major flood stage for at least another week. >> This is this is 21. Wow. This is 21 6 I believe. >> I'm Todd Dos is scrambling to protect his Davenport body shop where the river may not crest until Monday. >> They say it's going to be that your flood stage. You better get your sandbags and fan delivered and get a plan. >> This as brutal storms batter the south blanketing the ground in massive hailstones. Some 12 million under threat across the region in Florida. Damaging winds ripping a 30 year-old tree out by its roots. Back here along the Mississippi residents stuck in a high stakes waiting game that's far from finished. >> Leicester. All right, Maggie Vest, but thank you. On an overseas trip in Jerusalem, Florida Governor Ron DeSantis was defiant today firing back after that lawsuit by Disney DeSantis saying the company is getting special treatment. That means to end. Gabe Gutierrez spoke with this. Anderson has details. Thank you so much. Tonight for the governor. Ron DeSantis on the world stage touting his pro business record but also firing back after Disney's lawsuit which alleges he orchestrated a campaign of government retaliation pushing to scrap Disney's decades-old deal with Florida that allowed the company to govern itself. Main employer in your state now is coming back and saying your anti business in this new lawsuit. >> What's your response to that? The idea that somehow the pro business means giving companies their own governments, that is not what a free market is all about. They're upset because they're actually having to live by the same rules as everybody else. >> He calls the suit political what Disney calls his actions payback. The company's opposition before this law that bans classroom instruction on sexual orientation and gender identity. The culture battle comes as for GOP operatives now tell NBC News DeSantis could enter the presidential race by mid-May. He's not been is global trade mission widely seen as a way to bolster his foreign policy credentials. >> Iran's pursuit of nuclear weapons. >> Creates a risk. Today he met with Israeli Prime Minister Benjamin Netanyahu. Would you talk about what about Iran? Talked about his real U.S. relations. He's a friend of Israel. The prime minister sitting down with NBC News declining to pick sides in the U.S. presidential race. But speaking warmly about the Santas as well as his potential rival. >> President Trump has been a great friend of the state of Israel as well. He did great things for the state of Missouri like recognizing Jerusalem as Israel's capital. >> Our latest NBC News poll shows DeSantis trailing former President Trump by 15 points in a potential primary matchup. The governor rounds out his foreign trade mission in the United Kingdom tomorrow. >> Leicester? Alright, Gabe Gutierrez, thank you. Former FOX News host Tucker Carlson has made his first on-camera appearance since he was dismissed as we learn more about what may have led to his firing. Stephanie Gosk has details. >> Off the air does not mean out of sight. Tucker Carlson's video on Twitter viewed nearly 20 million times. Good thing. You notice when you take a little time off is how unbelievably stupid most of the debate you see on television are. >> Notably Tucker Carlson did not mention FOX News nor the reason for his departure messages revealed because of Dominion voting Systems. Defamation lawsuit may have played a role according to The New York Times. 2 people with knowledge of the discussions say the night before FOX settled the case with Dominion for nearly 800 million dollars, top executives and board members learned of, quote, highly offensive and crude messages calls and sent in the past and it triggered a crisis. FOX has not publicly provided a reason for getting rid of Carlson. Meanwhile, the 08:00PM audience on the FOX News Channel Tuesday night was down about 50% from a typical night with caution. Do you think he has the power to take those people who watched him loyally someplace else and is there a platform that makes sense? >> He undoubtedly has the power to take his audience from FOX News. >> But maintaining the same influence may be harder. >> When you are on television, you have a long tail on the Internet. People are training your videos. You don't get as long tail when you do. You know friends, Tucker Carlson DOT net, you know. >> A high-profile host out of a job and but not out of the public eye is going to Stephanie Gosk, NBC News, New York. >> So we'll be back in 60 seconds with what could be a groundbreaking new way to lose Weight. Plus movie Magic. The incredible AI technology. Transforming Hollywood stars in an instant. We're back now with what could be a game changing treatment for obesity. It's a drug already approved for treating type 2 diabetes and promising new results from a clinical trial show. It helps with weight loss to Erin McLaughlin explains how it works. >> It's being billed by Eli Lilly has a new bar for weight loss. Very pleased with the results called Tirzepatide currently sold under the brand name on Jaro to treat type 2 diabetes. But if approved for treating weight-loss, analysts believe it could become the biggest drug ever. >> We'll bring on male more manufacturing capacity and throughout this year to help. >> Make sure we're able to meet demand in the marketplace. A clinical trial last year found the drug helps people with obesity lose almost a quarter of their body weight. Today, the company announced new results of a second clinical trial, which followed more than 900 adults with both obesity and type 2 diabetes. Finding patients last up to 15.7% of body weight. >> In about 16 months, weight loss is hard for patients with diabetes. And I think in America we have a lot of stigma out. Hey, you need to be able to do this on your own 2 separate IED work similarly to drugs like Ozempic and we go V also shown to cause weight loss. The difference that combines 2 medications together. The summary of that is that it helps your stomach feel full sooner for almost a year. Jennifer Huber has been taking the drug once a week to treat her type 2 diabetes. I get emotional. I'm down about 60 pounds, which that was not part of the plan to this drug change your life. It's changed my life, even though I'm a smaller person now I feel that and more visible society. It's been a good thing is that it had a good happy to us. Still, Jennifer says she's had to deal with side effects including nausea and constipation. She's worried to gain the weight back if she goes off the drug and doesn't know if her insurance will cover the medication beyond August really can't afford the $1200 are how much it would cost without insurance with billions at stake. Eli Lilly hopes the FDA will approve the drug for weight loss by the end of the year encouraging to millions longing for an end to America's battle with obesity. Erin McLaughlin, NBC News. >> There's more to tell you about. Still ahead, the next generation of Hollywood Magic. The incredible AI technology that could transform movie stars and our favorite films. There's a Star Nation shift underway in Hollywood as technology transforms how we see our favorite movie stars. And you won't believe your eyes. CNBC's Julia Boorstin puts the high-tech effects to the test in our series AI Revolution. >> Hollywood production is being transformed by artificial intelligence. Deep food is a visual effects company that specializes and what they call a facial replacement AI. >> That's a funny face as you make like to think. >> In about 30 minutes, they scanned my every expression to learn my facial movements. And 2 weeks later we put the algorithm to the test with a body double and a live camera. There we go. Not my hair, but it's totally my face. While visual effects have a long history in Hollywood, D voters, Precision and live render feature have won over celebrities like Kendrick Lamar who use their technology to where the faces of other celebrities, the traditional be effect scenario. It would be stuck in post and they would be able to see it until it's been a shot. You can impact actors wear the mask of another actor's face while they're shooting the movie rather than having to wait until it's all done to do the face swap. Absolutely. Yeah, Julie, you don't have to show up for work. De Puy du says it's working with studios to put actors faces on stunt doubles and even to revive deceased movie stars. How much is your technology threaten people's jobs? >> This enables people to do their jobs quicker, better and cheaper. But it is that it's a creative tool and it needs to be operated by creative people. >> But with all of this new technology come new concerns. The Screen Actors Guild telling us, quote, Our Goal is to ensure that our members are protected from unauthorized use of their names, voices and likenesses. We intend to expand those protections as AI uses are addressed. >> And movie sets like this one AI is not only being used to clone actors faces and voices. It's also being deployed to CGI and visual effects faster and easier than ever before. Wonder, Dynamics quickly transformed me into these characters. Their AI technology can replace a human actor with a computer generated figure in hours. It's waving its arms around the way I live my hands tonight. I. >> Actor and company co-founder Tye Sheridan was inspired to improve visual effects after his experience wearing motion capture sensors on Steven Spielberg's ready player one. >> Well, as art till stories that were bigger than our pockets. And that's really kind of what led us to started his company along with his co-founder Nicoletta Dora Vick. >> Sheridan is hoping to make premium visual effects easier and more affordable. I one minute scene like this would normally take weeks to render. >> With our technology really hoping to bring it to a day or a couple hours depending on what shot is. So it becomes a much faster but also more cost efficient. Exactly and more accessible because all you need is a browser. The browser and a camera. >> Wonder Dynamics says hundreds of thousands of users have signed up to try its platform and productions in the works for Netflix are already using. It is going to eliminate the need for actors. >> Absolutely not. A were no. I think it's good. If anything, I think it will create more opportunities for actors to be in these type of film. >> And if it works, what used to be science fiction can become an AI reality. >> Julia Borst an NBC News Los Angeles and that's nightly news for this Thursday. I'm Lester Holt. Take care of yourself and each other. Good night, everyone