this is "nightline." >> tonight, an emotional verdict. the stunning conclusion for a former sheriff's deputy charged with murdering his young wife. his defense team arguing her death was a suicide. and the prosecution turning up new witnesses with dramatic accounts pointing to murder. >> he proceeded to say, "i shot my wife." >> the final word tonight. plus professional pranksters. these three guys will do anything for a joke. some feel these pranks cross the line. but their videos are earning the youtube stars millions of subscribers. and now they're taking their antics to the big screen. and athleisure b.

beyonce drops a new line. you can run the world while working out. first the "nightline 5." johnson's believes bath time is more than cleanse recognize are your loving touch stimulates his senses and nurtures the mind. lather and bubbles help enhance the experience. why just clean your baby when you can give him so much more? ♪ ♪ ♪ come on and do it come let's go ♪ ♪ got to get moving come on let's go ♪ >> number one in just 60 seconds.

good even. thanks for joining us. tonight a dramatic verdict in a murder mystery four years in the making. was ashley fallas, a young

mother struggling with depression who killed herself? or was she as the prosecution argued shot dead by her husband? who then managed a intestine administer cover-up? we bring you inside the courtroom as the trial reached its emotional conclusion. >> juror 26, has the jury reached a verdict? >> yes, we have, your honor. >> reporter: after less than four hours of deliberation a colorado jury returned with a dramatic verdict for tom fallas, the former corrections officer accused of brutally murdering his wife ashley. he sat silent and stone-faced while the two women on his defense team wiped away tears as the often emotional 13-day trial finally came to an end. they were by many accounts a happy couple. >> happy new year! >> reporter: seen here dancing away the last hours of 2011. having hosted a party welcoming the new year together. but shortly after midnight, minutes after the last guest left -- >> are you getting this too?

>> reporter: a frantic 911 call. >> my wife just shot herself in the head! please help me! please help me! >> reporter: fallas' piercing cry for his wife. >> help me now, heashley no, ashley no! listen to me, hey! >> reporter: ashley,oung mother of three, appeared to have taken her own life. found in a pool of blood in her bedroom, dying from a single gunshot wound to the head, her children still inside the home. >> no! >> sir -- >> stay here! come here, you stay here! you're not leaving me! >> reporter: at the time, five law enforcement agencies ruled it a suicide. but four years later, the same man heard here begging for his wife to hang on -- >> you're not leaving me! don't leave me! stay right [ bleep ] here! look at me! >> sir! >> look at me! you hear me? you can hear me, i know you can hear me! >> reporter: standing trial for her murder.

the prosecution asserting that beneath the loving husband facade was an angry and volatile man prone to outbursts. >> i just told you! >> why are you -- that is not from you -- >> you know, yeah, it is. when you shave your chest, you sit there and i do this all frickin' day -- >> you're trying to make more scratches right now. >> oh my god. >> reporter: in the interrogation video obtained by abc news, early clues according to the prosecution that fallas was hiding signs of a fight with his wife. >> it was a playful hit that she hit me earlier. it was in front of people. it was just like a boom. >> reporter: questions involving the angle of the bullet wound as to whether it was even physically possible for ashley to have shot herself. >> tom, look at me. she'd have to go like this. clear back here. it isn't where she could easily reach. >> i didn't -- oh my gosh. >> reporter: and witnesses who suggests they overheard a struggle. >> there was somebody awake and they actually heard your argument and your conversation between you and your wife. >> really, what conversation was that?

>> she's telling you to get off of me, get off of me. and you're saying, don't leave me, don't leave me. >> oh -- >> explain that. >> reporter: fallas losing his temper, declaring his innocence. >> i didn't shoot my wife! >> reporter: ashley's mother, jenna fox, thinks he did. pointing to tom fallas' behavior the day of ashley's death. >> the very end of the night, i think his behavior towards her was very threatening and very volatile and very scary. >> reporter: her account seemingly confirmed by stunning new evidence. two eyewitnesses testifying that they heard fallas confess to the crime. >> i heard him screaming, "i can't believe i shot her, i can't believe she's dead." >> reporter: the next-door neighbor, nick glover, just 15 at the time. >> what i heard him saying, "oh my god, what have i done, oh my god what have i done." >> reporter: testifying he overheard fallas confessing to his own parents. >> he proceeded to say, "i shot my wife." you can't hear something like that and forget about it.

that's going to be embedded in your mind for years to come. >> reporter: all damning testimony. but even before the defense started presenting its case, reasonable doubt was creeping in. that confession glover said he overheard fallas make to his parents, his father said it never happened. >> did tom ever make a statement to you that he shot ashley? >> not at that time, not at any time. >> reporter: the defense also poking holes in former officer graves' account, who was eventually fired for allegedly lying about the case. >> this is one of those cases where there just may have been too many unanswered questions. for the jury to even seriously consider convicting based on proof beyond a reasonable doubt. >> reporter: and perhaps the biggest blow to the prosecution's case? two of their key witnesses actually appeared to support the defense during cross examination. the state's own crime scene investigator suggesting it may have been a suicide. >> the temple, the entry wound

right here on the hairline, you can see the red dot over here on the back side of the head. >> reporter: and ashley's psychiatrist. >> did she seem depressed to you? >> no, she did not. >> did she seem suicidal to you? >> no, she did not. >> reporter: then seeming to backtrack. >> she called herself, reported herself as a failure as a result of her second miscarriage, correct? >> correct. >> if you had known she thought she was pregnant twice and miscarried twice when you saw her on december 2011, you might have thought of that as being a red flag, that is true? >> i certainly would have. >> would all these things change your thinking about miss fallas' state of mind? >> yes. >> reporter: the defense painting a picture of a depressed mother, showing the bottles and bottles of antidepressants found in the bedroom, and even the existence of an old suicide note. >> ashley said on july 24th, 2011, dear tom, i'm sorry with all that i have caused. i'm not happy about it. i'm sorry for your pain but i

can no longer go on living this life. >> reporter: perhaps the most dramatic forensic evidence? the defense presenting gunshot recess due. typically found only on the person who fired the gun. >> ashley fallas had gsr on both of her hands. tom fallas didn't have any. >> reporter: the prosecution's case was so weakened that the defense only called two witnesses and kept tom fallas himself off the stand. in the three-week-long trial the potential star witness saying only this -- "i will not testify." >> it was clearly a smart decision by fallas' lawyers not to put him on the stand. because the minute you put a defendant on the stand, the whole case often ends up hinging on the credibility of that person. here the evidence was not particularly strong. and so there was no reason from the defense's perspective to have him testify. >> reporter: the reasonable doubt culminating in today's dramatic verdict delivered just

hours ago to a hushed courtroom. >> we the jury find the defendant thomas fallas not guilty of murder in the second degree and all lesser included offenses, signed by the jury foreperson. >> this case is over. prosecutors can't appeal. >> any good prosecutor is going to know, based on the evidence that they had, that this was at the very least a tough case for them. >> the original 911 call was made -- >> reporter: tomorrow night on "20/20," ryan smith will take viewers inside the house where it all started with one of the first responders. >> as you left this location, what was your gut telling you about what happened? >> my original feeling was we were investigating a homicide. >> now? >> now i believe she committed suicide. >> don't miss "20/20" tomorrow night at 10:00 eastern for an in-depth hour on the fallas trial. up next, three mega pranksters are headed to the big screen. and later, queen bee has a new

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♪i am beautiful in every single way♪ ♪words, can't bring me down♪ friday is officially april fools' day. so you might have a good gag planned. but it probably won't match the high jinks of youtube's natural-born pranksters. their over the top stunts garnered millions of youtube followers. do they ever cross the line in the name of good fun? my "nightline" coanchor dan harris sat down with the pranksters for our series "social stars." >> reporter: yes, this is a grown man playing with a rubber

snake. >> snake! >> reporter: but for him and his compatriots it is a serious and lucrative business. >> today we're really bad beekeepers. >> go that way clap! >> reporter: they actually do this for a living. theroux man atwood, dennis brody, and vitale. three youtube stars who call themselves the natural-born pranksters. >> oh my god! oh my god! >> why do you like pranks so much? >> it's that reaction, it's the adrenaline, it's the -- >> somebody needs to do it. somebody needs to do it. >> reporter: we're not talking about high culture here. >> [ bleep ], [ bleep ]. >> reporter: their antics range from the boyishly silly -- >> tell me if it stinks. >> reporter: to the edgy and controversial. >> so cute, they won't stop

crying. >> reporter: they find humor in the unlikeliest of situations. >> where's the line? >> him and i know the line. >> he doesn't know the line? >> he steps over the line. >> there is a moral/ethical line? >> i think that's what, you know -- he'd go as far as blowing up this kid in this video. right? >> i've done that. >> what? >> you still love me, right? >> [ bleep ]. >> reporter: pushing the limits has paid off big-time for these professional pranksters. they each have multiple youtube channels with more than 29 million subscribers among them. racking up nearly 4 billion total views. even landing roman on the "forbes" list of top-earning youtube stars. >> so i'm getting the natural-born pranksters right now. >> reporter: they've also found themselves on the world stage. >> i'm about to go in the middle of the field of the world cup

finals. >> reporter: the streaker during the 2014 world cup final was vitale. >> i got my boots on, socks, then i just went for it. >> as you jumped over, were you freaking out? a little bit? >> it's the best adrenaline i ever had. i literally have never felt like this. tingles. all the flashes. everything. i knew so many people are going to see this. i went to jail for an hour in brazil. and paid a $100 bail. and i was out. >> reporter: you could say they're the jackass for millennials. >> whoa! >> reporter: how much inspiration do you draw from "jackass"? >> i remember saying, i'm going to do this one day, i can do something just like this, in that same arena. >> reporter: like the "jackass" crew before them they're taking their act to the big screen. their first film called "natural-born pranksters" and lands in theaters fittingly on april fools' day. >> i can do whatever i want!

>> when you planned these pranks how does that process go? >> it was brutal. i think we ended up with 400 pranks. and the movie has about 30, 32 pranks. >> the legal process. >> congratulations. yvonne had a healthy pregnancy -- >> reporter: sure to raise eyebrows this scene, a pregnant woman due to deliver any day, introduces her husband to their surprise bundle of joy. >> is this our baby? >> i was meaning to talk to you. >> it's so difficult to find that specific accomplice. someone that's about to have their baby. also willing to set their husband up. >> you don't want to hug your baby? >> i just got the text. >> oh [ bleep ]! >> reporter: accomplices setting people up just part of the fun, like when this woman, in on the joke, leaves her boyfriend to go

use the porta-potty. a fake drunk driver erratically takes the place by storm. >> whoo! >> hey, hey! holy [ bleep ]! >> reporter: shock. >> oh my god! >> i'm so sorry. >> reporter: relief when it turns out it was a joke. >> [ bleep ], [ bleep ], [ bleep ]! >> reporter: sometimes these punch lines can fall flat. >> hey! >> reporter: extremely flat. even dangerously so. the pranksters have found themselves -- >> what are you doing, bro? >> reporter: in hairy situations. >> what are you doing to my car? >> getting gas. >> get the [ bleep ] away from my car! >> reporter: they've found themselves in handcuffs. >> let go! >> american police. >> you're on camera! >> get on the ground now! >> have you ever been doing a prank where you thought, i'm going to get hurt? >> oh, yeah. >> there was a time in finland.

the prank was, we're kidnapping a woman in front of people. and we put her in the trunk. >> why did you think you were going to get hurt? >> well -- >> our heads got cracked. >> some guy was trying to fight us. >> that's the first time i've had police grab their guns. >> good joke. >> is there a prank you would not pull? >> in washington, d.c. i was going to jump the white house wall. >> over the fence? >> yeah. >> ding dong ditch the white house. >> i can't do it because i'm not a citizen and i know i'd get deported immediately. but when i get my citizenship -- white house. >> reporter: the pranksters themselves insist it is all in good fun. and they point out that sometimes their stunts perform a public service. ♪

>> reporter: like giving food to the homeless. they like to think of themselves as just three oversized children making people laugh and trying not to get hurt in the process. >> lots of bees, run! >> reporter: for "nightline," this is dan harris in new york. >> just a joke! up next, singer, actress, new clothier? beyonce announcing a new clothing brand. ready to run the world. the fashion world. alriwe could do tacos.hink boys? we could do some thai. ooo... how 'bout sushi, eh? (dog yawns) no, we're not having barbecue... again. (dog groans) why? because you're on four legs, and i'm on two... and i'm driving. that's why. (dog whines) sushi it is.

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ah, beyonce. she's already a cultural icon, amassing millions of followers known as the behhive. their queen announcing a new leisure line today. athletics meets leisure wear. it's got the behhive buzzing. ♪ who run the world girls >> reporter: he may already run the world. but queen bey's adding to her already formidable empire with a

new athleisure line. joining the ranks of other celebrities who have run away with the trend. fabletics by kate hudson. calia by carrie underwood. ivy's line, a nod to her daughter blue ivy and the park she grew up going to. >> the park became a state of mind. the park became my strength. >> reporter: and on the may cover of "elle" magazine. ♪ let's get physical >> reporter: it's not a new concept. celebrities have been getting physical since the '80s. from jane fonda's original workout -- >> nice big stretch. >> reporter: to the markey mark workout with "golden girl" fitness love from the young at heart routine. >> i feel lousy! >> reporter: these hollywood stars keeping you looking flawless for decades. ♪ ♪ i woke up like this flawless >> reporter: with ivy park queen

bey's certain to have fans in love once again. ♪ so pretty in love >> thanks for watching. tune into gma tomorrow. and as always, we're online 24/7 on our "nightline" facebook page. and at abcnews.com. good night, america.