supported life at one time. >> thanks for joining us. nightly news is next. we will see you coming up at 6:00. >> good night. see you soon. stunning admission as the marathon bombing trial gets under way in boston. what the defense told the jury that just about no one saw coming. pattern of bias in the wake of the uproar in ferguson. the feds now releasing in shocking detail how police treated people there for years. death spiral, that's what could happen to obamacare. tonight, a warning at the supreme court with health care coverage for millions hanging in the balance. nbc news exclusive, iran hitting back at israel's allegations about the bomb. and is it the last blast of winter? a monster storm taking aim. snow and flood emergencies across a huge part of the country. "nightly news" begins now.

>> announcer: from nbc news world headquarters in new york this is "nbc nightly news." reporting tonight, lester holt. good evening. any notion that the accused boston marathon bomber would fight for his innocence went out the window today on the first day of this trial when his lawyer bluntly told the jury his client did it. the admission dzhokhar tsarnaev and his late brother planted the bombs that killed three and injured 260 others, still for those gathered in the courtroom it was stunning to hear. but it does not necessarily mean a slam dunk for the prosecution. in fact, that admission sets the stage for a question larger than tsarnaev's guilt or innocence. peter alexander is covering the trial for us in boston. >> reporter: inside boston's federal courthouse today, bombing suspect dzhokhar tsarnaev's defense lawyer made a stunning admission, it was him. tsarnaev showed no emotion wearing a dark blazer and open collared shirt. he faces 30 charges, many that could carry the death penalty

including using a weapon of mass destruction resulting in death. misguided acts that were inexcusable, admitted the explosions extinguished three lives. among those victims, 8-year-old martin richards. the prosecutors showed his smiling face and graphically detailed his death as his parents wiped away tears. taking the stand today, rebekha gregory, remembers hearing her son calling mommy, mommy and thinking to herself, god, if this is it, take me, but let me know noah is okay. cindy was badly wounded. i remember feeling i was just going to sleep, felt almost peaceful, she said. i was fading fast. sarah wants to see tsarnaev punished. >> i think it's important that somebody like that isn't ever out in the public again. >> reporter: the jury made up of ten women and eight men will also be shown never-before-seen surveillance video of the defendant placing the pressure cooker bomb right behind a row of children. he pretended to be a spectator but had murder in his heart, the prosecutor said.

adding, he believed he was a soldier in a holy war against americans. the defense tried to shift the blame to tsarnaev's older brother tamerlan who died when he was accidently run over by his younger brother during a shootout with the police. they insisted it was tamerlan who self-radicalized. dzhokhar followed him. still, the defense said we will not argue that tamerlan put a gun to dzhokhar's head. prosecutors found a message he scrawled inside. i ask allah to make me a martyr, offering what they say is a motive for tsarnaev's bombing attack. he thought it would help secure him a place in paradise. the real question dominating this trial is whether suspect dzhokhar tsarnaev should be put to death. as a member of the defense team said earlier this week, lester, this case is all about sentencing. >> peter alexander, thanks. cynthia mcfadden is our senior legal correspondent.

cynthia, let's pick up right there. it's all about sentencing. they've admitted he did it. now what? >> well, what happens now, as peter pointed out, ultimately there's really only one question before the jury, whether this 20-year-old should be sentenced to life in prison or death. the prosecutor's strongest case for death comes in laying out in a very meticulous way, lester, the horrific nature of the crime. the calculated planning, the cold-hearted placement of the bomb behind a group of kids, the death, the injuries, this takes time. from the defense point of view, they're going to want to paint a picture of the defendant as a kid respecting his older brother and dominated by him and afraid of him and did what he did because he was afraid not to. and it's worth noting that in the last 39 years, only three people have been executed by the federal government. this jury's going to have to decide if tsarnaev is going to be the fourth. >> this may go on for a while. >> it may indeed. >> cynthia mcfadden, thank you. another major development in another case that has gripped the nation. today we finally got the full

and damning report that we got from the feds. it alleges in detail a pattern of racial bias in the police department in ferguson, missouri. but the department of justice who released the report found no such evidence in the case that launched this such evidence in the first place, the police shooting of michael brown. ron allen is back in ferguson for us tonight. >> reporter: despite months of passionate demands from protesters in ferguson, federal investigators decided not to charge former police officer darren wilson saying he feared for his life, acted in self-defense killing the unarmed teenager michael brown. closing that civil rights case while demanding ferguson make sweeping reforms to end what officials insist is a widespread pattern of racially biased policing and using court fines to raise city revenue. >> this investigation found a community that was deeply polarized. a community where a deep distrust and hostility often characterized interactions between police and area residents. >> reporter: the report found shocking instances of alleged abuse including police almost

exclusively using dogs against black suspects, excessive force against the mentally ill and erasing all fines issued to members of the police and courts. so the doj is demanding ferguson change its stop, search and arrest procedures. limit excessive force and use tasers and dogs only if a supervisor is present. embrace community-based policing. and recruit, hire and promote diverse officers. a pastor a protest organizer, says he prays change will come. do you think there's a willingness here? >> yay and nay. i say yay the simple fact so much attention brought in on it. nay because once the attention gets off of it, it will go back to the way it's used to being done. >> reporter: a statement from brown's parents, while we are saddened by this decision, we are encouraged that the doj will hold the ferguson police department accountable for the pattern of racial bias, adding that their hope that true change will come not only in ferguson but around the country. tonight, here ferguson's leaders are responding to what many are

calling a scathing indictment and they say they are taking immediate action. for example, firing one employee for sending racist and disparaging e-mails and two others face disciplinary charges as the investigation continues. lester? >> ron allen, thank you. high drama at the supreme court today. a lot of eyes on this one. a legal challenge that could doom obamacare as we know it. health care coverage for millions of americans is hanging in the balance. and as our justice correspondent pete williams reports, the law's future could hinge on just four words. >> reporter: what's at stake? >> $6,000 a month just for drugs. >> reporter: ask david tedrow whose non-alcohol liver disease left him bedridden forced to sell his business. >> my liver was ceasing to function. and i was dying. >> reporter: what saved him, he says, was the launch of obamacare and the federal subsidy that came with it allowing him to afford insurance and get a liver transplant.

>> oh, my gosh, i'm a completely different person today. i'm alive. >> reporter: he's one of the 7 million americans who get their insurance and the subsidy through healthcare.gov, the federal marketplace or exchange. their average premium, about $100 a month, would be nearly four times that without the subsidy. too much for many to afford. the question today for the supreme court, who's entitled to that subsidy? only 16 states now have their own insurance exchanges up and running and obamacare opponents say the laws's own words mean subsidies are only for insurance bought on "an exchange established by the state." >> a clear purpose of the statute was to encourage states to establish their own exchanges. >> reporter: but justice kennedy said pressuring the states that way might be unconstitutional. "the states are being told either create your own exchange or we'll send your insurance market into a death spiral."

and justice elena kagan said reading it as a whole and not just an isolation means everyone gets the subsidy. if the challenges are right that the subsidies are really are so limited, quote, you really think congress is just going to sit there while all of the disastrous consequences ensue? wouldn't it fix obamacare, he wanted to know. chief justice robert's vote said almost nothing today making prediction impossible. but did not seem as hostile as the white house had feared. lester? >> pete, thanks. can you believe it our winter weary nation under a threat from snow ice and flooding is about to get hit again. 100 million americans are under winter weather advisories in 28 states with states of emergencies already declared in alabama and mississippi. nbc's john yang has more on the winter that just won't quit. >> reporter: snow, sleet and ice

overnight gave way to river flooding across the northern part of the country. ice jammed streams and creeks in the ohio river valley inundating roads and communities like this one in west virginia. in ohio a woman had to be rescued after her car was swept into a river. outside pittsburgh, blocked roads forced boat rescues and evacuations. >> we had a nice little experience go over a couple pieces of ice and everything. >> reporter: flood warnings and closed schools from louisville to memphis to cincinnati. in the northeast snow triggered massive roof collapses including a dairy farm in central new york, and the old bayside expo center in boston. the city is less than two inches shy of a season snowfall record. >> i can't wait until spring. i'm counting down the days. >> reporter: boston thermometers did hit 40 degrees today for the first time in a month and a half, ending the city's longest cold spell on record.

in the deep south, dramatic 20-degree temperature drops. in greenwood, mississippi, 79 to 59 in just 26 minutes. and in greenville, mississippi, 74 to 53 in just 11 minutes. more than 2,000 flights canceled from dallas to chicago to new york. and at the louisville airport, travelers tried to escape the bluegrass state before it turned white. >> i would rather be stuck in at home. >> reporter: here in louisville the snow's not expected to stop until sunrise tomorrow. this city rarely sees one big snowfall in a winter. this is the second big snowstorm in just two weeks. lester? >> for what it's worth, it's pretty behind you, john yang. thanks. dylan dreyer is in boston tonight. dylan, where can we expect the worst? >> reporter: kentucky, northern missouri and arkansas. but it is going to spread east as we go into tonight and tomorrow morning.

it is a messy morning commute from nashville to washington, d.c., up into new york city. it will exit through the day on thursday, but still an icy evening commute all the way down into raleigh. now, we're looking for about 6 to 9 inches back through the ohio river valley, but even d.c. could walk away with six inches of snow out of this one. back behind this cold front we are talking about possibly breaking record cold again. chicago starts off tomorrow morning at 1 degree. lexington, kentucky at zero. we're looking for teens to make their way into the northeast by friday. but, lester, we are still looking for that warmer weather pattern to arrive next week. >> dylan, thank you. we're getting late word tonight of an attack on the u.s. ambassador to south korea, ambassador was seriously injured, reportedly with a razor while on his way to a lecture in seoul. he was rushed to a hospital according to south korean news reports. his injuries not life threatening. the attacker was arrested but so far his identity and motive remain unknown.

now to an nbc news exclusive, as secretary of state john kerry concludes the latest round of talks over iran's nuclear program. his iranian counterpart is firmly pushing back against that fiery speech israeli prime minister benjamin netanyahu delivered to congress yesterday. warning against what he called a bad deal that will lead to a nuclear iran. in an exclusive interview with ann curry, mohammad zarif accuses netanyahu of fearmongering and distorting facts. >> mr. netanyahu has been proclaiming, predicting that iran will have a nuclear weapon within two, three, four years, since 1992. iran is not about to develop a nuclear weapon. we don't want to build nuclear weapons. we don't believe nuclear weapons bring security to anybody, especially not to us. >> we were able to find the tweet that he referred to from the supreme leader, "this

barbaric, wolflike and infanticidal regime of israel has no cure but to be annihilated." mr. foreign minister, can you understand why jews and others would take umbrage at that kind of language? >> no, i won't. this is a regime. we're talking about mr. netanyahu who has butchered innocent children in gaza. we're not talking about annihilation of jews. we never have and never will. for somebody who comes to u.s. congress, tries to create this hysteria about something that doesn't exist. we never had a bomb. we will never have a bomb. but he does have a bomb. he has 200 nuclear weapons. >> why should americans trust iran on this? >> well, we're not asking anybody to trust us. and we are not going to trust anybody for the time being. we take one step at a time. we're not asking for trust. we are asking for verification. and we are accepting

verification. >> ann curry with iran's foreign minister mohammad zarif. those nuclear talks will resume on march 15th. it's a busy news tonight. a lot to tell you about. a firestorm over hillary clinton's private e-mails. up next, new revelations about what was being kept in her home as subpoenas now start flying. also ahead, a big announcement tonight about the menu at mcdonald's.

we're back now with some new revelations tonight about hillary clinton's communications when she was secretary of state. not only was mrs. clinton using a private e-mail account instead of an official one, a new report claims she was storing them on a server at her own house. now her political enemies in congress are demanding a look at them. our kristen welker has the story. >> reporter: speaking to a friendly audience in washington last night, hillary clinton ignored the e-mail controversy. but today republican lawmakers investigating the benghazi attack have subpoenaed all of clinton's relevant documents after revelations clinton exclusively used her personal e-mail account while serving as secretary of state. >> whether it's unprecedented or not is very unusual. >> reporter: and today the associated press reported clinton's personal e-mail account was linked to a server registered to her home in chappaqua, new york. tech experts say that gave clinton extraordinarily control

over her files. >> it's a large leap of faith to trust someone with that level of dominion over their own communications when they're representing a large organization. >> reporter: but did she violate federal guidelines? her aides and supporters say no. >> obviously they kept the records because many, many e-mails have been turned over. so records were kept. >> reporter: when clinton was secretary of state, the rules required officials using personal e-mail accounts to ensure their records were preserved in the appropriate agency recordkeeping system. but there was no deadline for turning over documents. >> that has since changed, but that was after she left. >> reporter: clinton finally turned over more than 50,000 pages of documents last year after the state department asked for them. so far, clinton has left her explanation to her supporters. the potential political impact of the e-mail controversy was blunted today with reports that republican jeb bush also used private e-mail for public business when he was governor of florida. but his supporters point out there were no regulations against that. kristen welker, nbc news, the state department.

when we come back here, why the man who invented something millions of americans use every day now says he wishes he never did.

mcdonald's announced today it will change its menu to begin serving chicken that's antibiotic-free. something chipotle and panera have already done as more consumers want food with natural ingredients. and because mcdonald's is such a giant in the restaurant business, this move is expected to have a major impact on the poultry industry in america. so many of us get our caffeine buzz from them every day, but now one of the men who invented keurig k-cups says he sometimes regrets it. in an interview he says k-cups are like quote, a cigarette for coffee a single-serving delivery system for an addictive substance. k-cups aren't recyclable but the company aims to change that by the year 2020. when we come back, no one's going hungry on her watch. even if she has to spend all her

retirement money on it.

we hope you'll be inspired by our final story tonight. over 14% of u.s. households don't know where their next meal

is coming from, according to the most recent findings. nowhere is the problem worse than in arkansas where one woman is giving everything, even her own retirement money, to put food on the table for thousands. nbc's mark potter has tonight's "making a difference" report. >> we're going to go 26 -- or 28 first. >> reporter: most every day charlotte tidwell can be found delivering food to people in need in ft. smith, arkansas, never slowing down. she's a retired nurse and widow raised in poverty who learned from her mother to serve others. >> i have the obligation to serve them. and to serve them in a compassionate, respectful way. >> reporter: charlotte runs a large volunteer food bank that serves nearly a half million free meals a year. >> she's just cool, man. she treats you right. >> reporter: she feeds 7,000 people a month paying for most of it with her own pension money. >> i don't worry about the money. i give it away. >> reporter: with her unpaid

staff, this 69-year-old works six days a week. >> i have those join me lifting, mark. >> reporter: you want me to help you lift it? okay. >> i have those that enjoy this. thank you. >> reporter: on this day she's delivering fruits, vegetables, meat and other food to low-income residents at a senior center. >> we thank the lord for this lady here. mrs. tidwell, for helping us out in a time of need. >> reporter: she also delivers food and kindness door-to-door. >> i feel a little bit better, thank you. >> reporter: and thrives on the good will. >> it's better than oxygen. >> reporter: back at the food bank she and her team work a will. >> it's better than oxygen. >> reporter: back at the food bank she and her team work a 12-hour day without heat to save money so they can buy even more food for anyone in need. mark potter, nbc news, ft. smith, arkansas. >> she's a remarkable woman. we've got more on charlotte's story tonight on our website. that's going to do it for us on

this wednesday night. i'm lester holt. thank you so much for joining us. and by the way, we know you can't always be with us at this time and that's why we're always available on demand. have a good night. breaking news. in oakland right now a shooting on 580 that's snarling traffic at this hour. good evening and thanks for joining us. i'm janelle wang in for ray mathai. >> this is a live shot right now from our nbc bay area chopper over the 580 backup. these are the two cars that were involved in this accident/shooting. this is what we know right now. at some point about an hour and a half ago the people inside these cars either had some sort of altercation and the cars crashed, or they shot at each

other and then the cars crashed. either way, one person was sent to the hospital, and the backup right now is huge. traffic backed up for miles. won't be getting better any time soon. the chp says at least maybe 7:00 before they open the lanes. possibly a little bit earlier at 6:30. two cars involved in this. the people inside involved in the shooting. again, one person is shot. that person is taken to the hospital. at this point the condition of the victim is still unknown. the motive also unknown. it happened about two hours ago, 4:00. the investigation taking place near the broadway off ramp. we're talking eastbound interstate 580 still going away from the city. two lanes at 580 broadway blocked, and at this point it's going to be a couple of hours before they reopen again. we'll keep you posted on the situation there on 580. now to a developing story overseas. a u.s. ambassador with bay-area ties is in the hospital after being slashed in the face by an