on our broadcast tonight on edge. a wild 48 hours as the crisis in ukraine rises up again. violence in the streets. fist fight in parliament and the u.s. is pointing directly at russia. in his defense, oscar pistorius breaks down on the stand as he describes for the first time publicly the night he shot and killed his girlfriend in the dark. fbi informant tonight. al sharpton answers questions about his past after new documents come out showing detaof information he gathered about organized crime. and new hope for people who have been told they will never walk again, now able to stand and move their legs thanks to a remarkable breakthrough. also tonight april 8th and why the white house says today's date is a bad day on the calendar for women. "nightly news" begins now.

>> announcer: from nbc news world headquarters in new york, this is "nbc nightly news" with brian williams. good evening and while the world has been distracted elsewhere suddenly once again the prospect of military action by one of the world's superpowers is being called a very real possibility. today the standoff between russia and what remains of ukraine took on a new urgency because there's violence in the streets once again. violence in parliament of all places. and people are tossing around terms like civil war again. it's largely pro russia violence in parts of ukraine and many are blaming russia for stirring it up with over 30,000 troops, let's not forget, on their side of the border. it's a dicey situation once again and we begin tonight with our chief foreign affairs correspondent andrea mitchell in our d.c. news room. andrea, good evening. >> reporter: good evening. the u.s. said today russia is trying to destabilize and topple

ukraine's pro western new government. even with using the troops on the border. rioting in cities across pro russia ukraine. government buildings burned. armed men in this video posted by ukrainian media occupying a security headquarters in luhansk, holding 60 hostages. a television station taken over in kharkiv, where police disarmed rioters. even in kiev, the capital, a fistfight in parliament between moscow partisans and supporters of ukraine's new government. secretary of state kerry told the senate today russia is behind it all. >> everything that we've seen in the last 48 hours from russia's agents operating in eastern ukraine tells us that they've been sent there determined to create chaos. >> reporter: russian foreign minister tweeted in english stop laying the blame at our door. testifying today before the same

committee he once chaired, kerry faced a buzzsaw of republican criticism. >> on the issue of ukraine, my hero, teddy roosevelt used to say talk softly but carry a big stick. what you're doing is talking strongly and carrying a very smallive stick. in fact, a twig. >> reporter: kerry hit back. >> teddy roosevelt also said the corrected belongs to the people who are in the arena trying to get things done. we're trying to get something done. that's a teddy roosevelt maxism. and i abide by it. >> reporter: republican critics are skeptical this will do any good but today vladimir putin finally agreed to the first direct talks between moscow and ukraine's new leaders also including the european union and secretary kerry to be held sometime next week. brian? >> andrea mitchell, starting us off in our d.c. news room. thanks, andrea. now to matters domestic. as we said at the top of the broadcast, the white house says

today april 8th is an important date for women because they say for the average american woman to earn what the average american male was paid last year she has to work all of 2013 plus all the way through today into 2014. in washington both parties staged events to show their support for women, the president issued executive orders. at the end of the day the protests nor the orders changed anything. american women still make an estimated 77% of what men do. in south africa today oscar pistorius described an excruciating detail how it was he shot his girlfriend to death in the dark last year on valentine's day. sobbing as he spoke, breaking down on the stand, he called reeva steenkamp's death an accident and not murder, as charged. mike taibbi was in the courtroom and has our report tonight. >> reporter: for the first time under oath oscar pistorius gave the central argument for his defense. >> i thought that there was a burglar that was gaining entry

into my home. the first thing that ran through my mind that i needed to arm myself, that i needed to protect reeva and i. >> reporter: gun in hand, pistorius made his way to the bathroom without his prosthetic legs. terrifie terrified, he said, shouting at the intruder, warning his girlfriend reeva steenkamp. >> i shouted for reeva to get on floor. >> reporter: he never heard her answer. as reeva's mother averted her eyes pistorius said he heard a noise in the bathroom and opened fire. >> before i knew it i put four shots through the door. my ears were ringing. i couldn't hear anything. so i shouted, i kept on shouting for reeva to phone the police. >> reporter: she didn't answer. he returned to the bedroom looking for her in bed. >> i thought reeva was there. >> reporter: it was then he told the judge that he began to realize exactly what he had done.

>> i think it was at that point, my lady, that it first dawned upon me that it could be reeva that was in there, in the bathroom. >> reporter: he said he put on his prosthetic legs and raced back to the bathroom this time with a cricket bat to pound the locked door open. >> at that point all i wanted to do was to look inside to see if it was reeva. i flung the door open, i threw it open. i sat over reeva and i cried. i don't know how long i was there for. she wasn't breathing. [ crying ] >> reporter: for the second day in the row the judge ended the session early, pistorius emotionally unable to continue. he'll be in the witness box again tomorrow but his account of the shooting is now complete. pistorius faces what could be a withering cross-examination as prosecutors pick apart the story he told so emotionally today.

mike taibbi, nbc news, pretoria, south africa. search teams off of australia still scanning in the hopes of picking up another possible electronic signature from the black boxes from the missing malaysia airlines jet. the wreckage is likely three miles down. it's all happening as those pingers are quickly running out of battery life, if they haven't already, which would make this incredibly difficult mission all that much harder. we get our report once again from tom costello. >> reporter: on this 32nd day of sear searching, frustration. after two days the australia american team aboard the ocean she would heard the pings that might have come from the plane's black boxes they have not heard the signals since. >> if we can get more transmissions, we can get a better fix on the ocean floor. which will enable a much more narrowly focused visual search. >> reporter: the pinger locator

is working at a depth of 4600 feet. "the washington post" illustrated today at 15,000 feet the ocean depth is a huge challenge. the empire state building stands at50 feet tall. the maximum depth a sperm whale can dive, 3,200 feet. the "titanic" was found at 12,500 feet. they found air france 13,000 feet down. if it's there flight 370 could be 15,000 feet below the ocean surface nearly three miles down. the underwater terrain is a volcanic plateau known as broken ridge, so deep oceanagraphers say the area has never been thoroughly charted. >> are there peaks and valleys that can hide the wreckage, is it soft mud, hard rock. it could be hard to get it off the bottom. >> reporter: search teams still haven't found a single piece of floating wreckage.

>> if you have a break up you expect to see wreckage. you expect to see debris, cargo. nothing. >> reporter: the cost of the search so far, roughly $44 million. and still no stein of flight 370. tom costello, nbc news, washington. he came to prominence as a civil rights activist decades ago and for a time the words brash and flamboyant would always be attached to al sharpton's name. in recent year, he's become a radio and talk show host, currently with msnbc. tonight newly released documents are shedding new light on another role from al sharpton's past that of fbi informant. we get our report tonight from our justice correspondent pete williams. >> reporter: al sharpton is as mainstream as a civil rights activist can be -- a frequent advise to the tot white house, a friend of attorney general eric holder, and nightly cable host on msnbc.

but it wasn't always that way. he was once a firebranded in a track suit. he championed cause celeb who claimed she was raped by whites then later discounted. now new didetailed documents detail his past. for nearly five years three decades ago he was an informant for the fbi helping agents build cases against suspected members of the mafia. was it scary talking to mob figures who killed people for a living? >> absolutely. i come out of a church, i come out of the civil rights community and i'm talking to a guy who is talking about killing people. >> reporter: documents published by the smoking gun website revealed what sharpton did to help the fbi gather evidence on members of the powerful gambino, and other powerful families. by recording conversations with mob boss known as the oddfather. he carried a briefcase fitted by the fbi with hidden microphones. >> this is not the sopranos on television. this is a real bad guy who controlled the music industry.

>> reporter: the fbi referred to sharpton in court documents as c.i. 7. meaning confidential informant. his name was never mentioned. law enforcement officials say the information he gathered helped the fbi get wiretaps for mob hangout, and he agreed to have a wire-tapped phone installed into his house in brooklyn. why did he agree to undertake such risky work helping the fbi nail the mafia? law enforcement officials said the fbi nudged him into it threatening to indict him after he met with an undercover agent posing as a drug agent, wanting to get a piece of the music piz. sharpton said that's not how it happened. >> if a civil rights leader has to apologize for inadvertently getting bad guys out of the music industry then it's a sad day in america. >> reporter: sharpton was never charged with anything and insists he's the one who volunteered to do it he needed no veiled threats to root out criminals. >> pete williams here with us in

our new york studios. thanks. when we continue, a mother with two sons caught in this national heroin epidemic, willing to break the law to get her hands on a drug that can save lives in an overdose. and later, a ground breaking therapy helping paraplegics do things once thought impossible.

more now in our series this week on the heroin epidemic in this country. tonight a closer look at how to reverse an overdose using a drug that can bring people back from the dead. it's known by the brand name narcam. first aid squads and paramedics carry it. it's saved thousands of americans. while the fda just last week approved a new form available by prescription this summer right now it remains illegal for anyone outside of the medical prof profls, leaving some families of addicts to take extreme measures.

here again is our national correspondent kate snow. >> reporter: outside st. louis this mom is so desperate to protect her family she's willing to break the law. >> technically this is illegal for you to have. >> yes. >> reporter: denise keeps those viles filled with narcam in her dresser. injected into a muscle it can reverse an overdose. >> if they are laying on the floor dead i am going to save their life. >> reporter: they are her sons ben and ryan both living with her, both heroin addicts sleeping in the rooms they grew up in. denise sent them to rehab but relapsed. ben is in treatment because he's young enough to be covered by his dad's insurance. he's been clean for two months. but ryan can't afford treatment and is still struggling. >> for some of us we have no idea what the attraction is. what does it feel like. >> like everything is all right. a warmth. that's what it feels like. it's just call. ing. >> reporter: it's so easy to get addicted and so easy to overdose. that's what scares denise.

>> ryan said he lost five friends. you probably knew their moms. >> i can't even drive by their houses. because i know my kid could be next. >> reporter: they've had close calls before. a couple of years ago denise had to take ryan to the hospital after he overdosed. >> they gave him a shot of narcam. i had never seen anything like it in my life. she was pushing it in his i.v. and he was coming out of it. before she even finished. >> reporter: that's what led her to chad her source for narcam. a recovering addict himself he gives it out for free to anyone who asks. but critics say that gives users like ryan a false sense of security. >> some people's argument is if you have more narcam around heroin addicts will use more. because they will know they have like a safety net. >> that's ridiculous. really is that what people think?

wow. you use if you want to use. i don't think i got narcam in the house. i can go use. >> reporter: a few hours after our interview with ryan, mom and sons meet at chad's apartment. ryan said he's been drinking with friends but as they watch chad explain how to use narcam it becomes clear he's high. >> you been using? >> i didn't use heroin. >> just drinking? >> yeah. >> reporter: denise and chad don't believe him. they think he's on heroin. >> are you more worried about him than you were this morning? >> yes. yes. >> reporter: denise never thought she would raise two heroin addicts or break the law to save them. but she says she has no choice.

>> your kids are everything to you. my goal every day is to keep them alive. it's so hard. >> reporter: her story is so painful and in many ways it's representative of the barriers a lot of families face when it comes to insurance coverage and treatment. we have more on that angle on our website. we had so much response using the #heroininamerica and i'll >> this is powerful stuff. thank you for being here to tell their stories. after a break we'll be back in a moment with new crash results that a lot of suv drivers are going to want to hear.

as we mentioned new round of crash test results making news tonight and the chevy equinox and gmc terrain were the only mid-size suvs to score high marks in this new round of data. popular honda pilots scored lowest of the vehicles tested.

we'll put the complete results on our website tonight. they contain bad news for a lot of widely owned vehicles in this country. ufo fans are going positively area 51 over some new pictures from the surface of mars. it's that bright light in the distance that has people talking in photo from the rover curiosity. nasa explains it as a distant cosmic ray, but some will have none of it. the women play tonight. it's possible one school will dominate both men's and women's ncaa basketball but for now all we know is this. uconn huskies are the champions beating kentucky 60-54, their second national title in four seasons. there's a growing noise in the background this season, however. this year's march madness was more commercial than ever. a "new york times" sports writer pointed out even the ladder and scissors were sponsored during the ritual cutting of the net. it's a multibillion dollar sport.

the athletes do not share in the vast ncaa wealth. only those who turn pro, which by the way, may include many of the kentucky freshman on the losing side of that game last night. if you were alive and a baseball fan 40 years ago tonight, there's a good chance you remember where you were and who you were watching with as the great henry aaron hit home run 715 off an al downing pitch to break babe ruth's record. sadly due to death threats he received at the time, tension was mixed within the joy of becoming the new home run king. a title millions of baseball fans still assign to the magnificent hammering hank. when we come back here a remarkable medical break through. a stunning moment for four men who were told they would never walk again.

finally here tonight a story that contains incredible images. it chronicles an incredible journey. the story of a medical breakthrough and how it impacted four men who were told they would be paralyzed forever. we get the latest from rehema ellis.

>> reporter: just standing up is an extraordinary achievement for rob and a medical milestone for people living with spinal cord injury. he was a star pitcher eight years ago when a car accidents left him paralyzed from the neck down but never paralyzed his hope. >> i'll find a way to overcome this. >> reporter: with an athlete's determination and strenuous exercise, he regained the use of his arms. three years ago a groundbreaking new therapy allowed him to do even more. to move his torso and legs, feel sensation, and regain control of important body functions. is this revolutionary? >> extraordinary. i was really shocked. >> reporter: today researchers from the university of louisville working with the christopher and dana reeves foundation announced three other paralyzed young men have had equally amazing results. >> the spinal cord has a capacity we never thought it had

before, and the more we learn about it, the more we can use that knowledge to help people with paralysis. >> reporter: here's how it works. below the injury doctors implant ad device the size of a pace maker and connect electrodes along the spinal cord. when turned on electronic pulses stimulate the nerves. which allows engagement of the muscles making movement possible again. dustin was paralyzed four years ago after a car accident said it's life changing. >> being able to move my legs, toes and ankles. huge change in my life for my self-confidence and my quality of life. >> it brought tears to my eyes, like it is now. it's just unbelievable. >> reporter: you are seriously moving here. there's more to do, but today excitement about a remarkable triumph of of science and the will of patients who refuse to give up. >> if i want to do it, i'm going to achieve it. >> reporter: rehema elvis, nbc news, new york.

positive note to end our broadcast this tuesday night. thank you for being we're us. i'm brian williams. we hope to see you right back here tomorrow evening. good night. nbc bay area news starts now. and i am thinking about it, but i am going to continue to think about it for a while. >> but in cheers, right now at 6:00, hillary clinton inches closer to a run. her comments raising an eyebrow. >> clinton talked immigration, energy and it was the earn eye of the presidential run that had people on their edge of their seats.

she tackled the big question with a maybe. telling tech innovators she's thinking about it. she already has some big endorsements, including gavin newsom. >> reporter: the lieutenant governor has been a big supporter for some time. she danced around the issue today, but the bottom line is she's still considering it. in the meantime, she's bringing in some money, between now and friday, three states, five appearances. some local experts say it could bring inasmuch as a million dollars. >> hello, everyone. [ applause ] >> reporter: former first lady hillary clinton is on a tour of the wrest coast that looks a lot like a campaign swing. >> she hasn't officially announced that she's running for president, but everything she's doing deaf kneltly points in that direction. >> reporter: today ms. clinton gave the keynote address at a marketing conference, commenting on the possibility of a run. >> the hard