what matt lowry did for us was to let us know that the fbi does not consider it sacred. >> whitehurstw the whistle on crime lab conditions leading the bureau to make changes. but he sees the same failures today. >> there's no accountability at all in the f.b.i. it's a systematic problem within the federal bureau of investigation. the fbi management category is defunct. it's a good old boy system. >> "america tonight" wanted to ask the fbi about its system for checks and balances and whether other agents and supervisors have been disciplined. the agency declined the request. >> the chain of command fail. you focus on that man. that little guy that because he had an addiction, he did what he did. >> there's about no evidence uncovered that anyone earlier than matt was engaged. >> the fact that he had a supervisor, and most likely had a supervisor do you think there should be anyone else held accountable beside kyle lowry, whether in the court of law or elsewhere. >> there was criminal wrongdoing all of which was perpetrated allow, and none of which was perpetrated by colleagues be they

. >> reporter: matt lowry always wanted to be in law enforcement just like his dad. >> he kept seeing i was in a uniform. so he went to his mama and asked her to make a little police uniform. >> reporter: he excelled in sports and school, graduated from the fbi academy with the highest honor. matt was living his dream, busting drug dealers mainly for heroin. but one day last september he disappeared. day turned to night. >> i then get a call from one of the other agents. bill, get to this location. they told me the location. it's matt. it doesn't look good. >> what goes through your mind? >> matt's been shot. i mean, that's the only thing that i'm thinking of, is matt is shot. and he's -- they found him somewhere. >> reporter: he hadn't been shot, but the answer to what happened is in these evidence photos obtained by "the washington post," empty heroin baggies in his fbi vehicle. evidence from cases he'd been working. >> heroin was in front of me, you know, every day. >> reporter: he'd first gotten hooked on prescription painkillers for a debilitating stomach problem, and when he cou

assurances measures will be taken to ensure my safety whatever location i will go. >> reporter: matt lowryfbi agent for five years. for more than a year during that time lowry was addicted to heroin and fed his habit by stealing heroin from evidence in several high-profile drug cases he worked on. after lowry was found passed out behind the wheel of his car last year, the fbi uncovered what prosecutors have called a premeditated and systemic cover-up by lowry to hide the fact he had been stealing drugs. prosecutors had to inform hundreds of defendants who had been arrested in undercover operations lowry stole evidence from. at least 25 defendanted convicted were released from prison because lowry tampered with their evidence. last march, lowry pled guilty to 64 counts. he told the judge he had become addicted to painkillers because of a medical condition. >> i'm appreciative that it's not a very lengthy time that was given to me, but i understand punishment must be given in my case and where i did wrong. i appreciate the judge and his leniency in my case. >> judge thomas hogan made it clea

. >>> former fbi agent matt lowry had a secret he was stealing heroin from evidence to support his own habit. earlier this year, lowry pleaded guilty to tampering with evidence and a lot of the people he put away is now become on the street. nbc's kate snow sat down with him to learn how his downward spiral started. something, you know, clicked in my head let me just take a little bit to start off these withdrawals. and then i will figure out later, you know, how am i gonna get through this? >> lowry has been clean for more than a year. he is now out on bond but still faces seven to ten years in prison. he is hoping this interview is going to help a lot of other people battling addiction. you can see kate's full interview on nightly news with lester holt at 7:00. >>> new fears after a recent rash of shark attacks. why some were staying on dry land this holiday weekend. >>> a maryland mom admits she did give kids pot at a birthday party, but didn't stop there. what she is accused of teaching a 6-year-old to do that led to her arrest. >>> the generous effort from these folks, making a ho