this is "nightline." tonight, mothers love, one woman's quest to try to prove her son's innocence by any means necessary. >> you were going to woo him. >> yeah, i knew i needed to use whatever i could. >> her son convicted of a murder, going undercover to secretly record a juror. her son now speaking out in jail. >> plus, an overturned conviction but still sitting behind bars. >> one of the worst things about this is people thinking i'm a murder. >> his mother's vow to win his freedom for good. "nightline" will be right back.

good evening. thank you for joining us. how far would you go if your child, your loved one, was convicted of murder and you believed they were innocent? that was a reality facing one mother who went to extreme measures, unbelievable measures, to try to set him free. here's my "nightline" co-anchor, juju chang. >> reporter: they say nothing is

as powerful as a mother's love. for true. >> i'm john's voice. >> reporter: this is the story of one mom's quest to try to prove her son's innocence ach he's convicted of a heinous murderer and the lengths she would go to, to set him free. >> i was going to look like a prostitutes. you don't let your children down. you fight for your children. >> reporter: it started in brooklyn in 2003, when 19-year-old mark fisher turned up dead. tonight police are trying to figure out who murdered a 19-year-old college student. >> his body was found dumped. on the streets of brooklyn new york. >> he was young. he was tall. he was an up and coming football player at his university, and he came to the city for fun. he just wanted to have a good time. and he ends up dead in brooklyn.

>> reporter: earlier that night, he was out with college friends, bar hopping in new york city. as the night wears on, mark heads to an after party in brooklyn at the house of john juca, someone mark had just met that night. tell me your impression of mark fisher. >> he had a personality that was likeable. >> reporter: was he intoxicated? >> yeah, he was drunk. >> reporter: were you? >> yes. >> these kids are sitting around, drinking, smoking weed, and antonio russo, a neighborhood kid kind of known to cops in the area. >> came to the party. >> was there anything between antonio russo and mark fisher that night? >> not that i saw. >> reporter: at sun begins to rise, mark is asked to leave the house party. >> he leaves the house, and he's next seen dead. >> reporter: mark's body was found two blocks away from john

juca's house. >> i cried and i just say why? it doesn't make sense to me. why would somebody do this to him? he was such a good person. >> reporter: just about an hour before he died he went to a convenience store and took out cash, just $20 at 5:25 a.m. and then walks back to the party. but the key detail is who goes on the atm run with him, antonio russo. >> the wallet was missing from mark fisher's body. so that created the suspicion that it was a robbery. >> the 19-year-old's body was found wrapped in a blanket at the end of a driveway there at that home, argyle rode. >> the blanket found with the body came from the juca home. that become as critical starting point for investigators. >> you got a call. >> i got a call from john. >> reporter: what did he say?

>> he said ma, you need to come home. and i said is everything okay? and he said you need to come home. >> reporter: and so you get home, frantic. what's the scene here? >> the press was on my lawn. >> reporter: already? >> yeah. and detectives were on my porch. >> reporter: but detectives aren't only closing in on john, they're looking at antonio russo, too. so there's a whole lot of smoke around antonio russo and john juca, but nothing that directly, forensically ties them to the crime scene, no dna, no fingerprints. >> reporter: nearly a year goes by with no arrests. but then? >> now, eyewitness news at 5:00. >> a college football star found dead more than a year without an arrest. hikier >> have you g the guy? >> any ent, anthony? >> they say you killed him for $20, antonio. >> in 2004, 13 months after the murder, antonio russo was

arrested. one of russo's first comments after he's arrested is, are you go being to arrest the others as well? and they say who do you mean? he goes oh, no, no, no, never mind. one month later in december, while he's returning from christmas shopping, john juca's arrested as well. >> reporter: did you give antonio russo the gun that night? >> no. >> reporter: did you put him up to it? >> no. >> reporter: did you have anything to do with the murder of mark fisher? >> no. >> reporter: so you believe the police arrested the wrong man. >> i know it. >> fast forward to 2005. john juca and antonio russo are on trial for this homicide. >> reporter: you sat in the courtroom every day. >> yes. >> reporter: was there any forensic evidence linking your son to the murder? >> zero. zero. this case was on testimony only.

he said-she said. testimony only. >> you had his long-time friend, one of his best friends, testifying against him. >> al cleary got up on the witness stand and said you had a .22 pistol, the same caliber at murder weapon. >> yes. >> reporter: and he also said you told him to show mark what's up. >> that's so ridiculous. that's not in my vocabulary. >> as the trial went on, here comes this special witness. john aveto. >> reporter: this jailhouse informant says john juca confesses to pistol whipping mark fisher and somebody else grabs the gun and shoots him. >> so it putting john juca right on the scene of the crime. >> reporter: and when he got up on the stand and said you confessed to him. >> i was so totally shocked. what i thought the jury would easily be able to see through it. >> after the prosecution made

its case, it was then the turn of the defense. but, as it turned out, neither the defense for mr. juca nor for mr. russo opted to call anyone to the stand. they rested their case. that was that. >> it's only an hour and a half later, and the jury comes back in and says guilty as charged. and john juca's taken out in handcuffs. >> it was torment. i turned white like a ghost, and i could not believe it. it was like my brain wouldn't even accept it. >> reporter: john is found guilty of felony murder and sentenced to 25 years to life in prison. >> i'm devastated. that doesn't mean i'm going to give up. i'm never going to give up. john is innocent. >> and she's already starting to think, how can i fix this? and she's not going to stop thinking of that until she comes up with a plan. >> when there's an injustice, fight. tremfya® is for adults with moderate to severe plaque psoriasis.

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. "nightline" continues. here again, juju chang. >> reporter: dorine juliano is devastated. her son is serving 25 years to life for a murder she says he had nothing to do with. she makes a vow to win his freedom by any means necessary. >> in 2006, she came up with this idea that she would investigate the jurors in the case. >> i was searching for the truth. i wanted to know why they came back with the guilty verdict. why? >> she has a one-woman sting

operation. >> a mutual friend of john's recognized one of the jurors. he said yeah, the guy with the balding head. he comes here to my house. the juror, juror number eight. was jason. >> although he didn't know john juca personal, jason aloe knew people who knew him. >> the key point here is less about how much did he know about these people and more did he intentionally lie to get on the jury. >> i said okay, so i need to speak to this guy. and that's when i began my undercover work. i started to know his routine. he hung out on the corner. he was talkin' about blondes. that's when i decided to go really blond. ♪ >> dorine changes her hair color. she puts on spike high heels.

she wears provocative clothes and changes her name to dee quinn. >> reporter: were you going to woo him. >> yeah, i knew i needed to use whatever i could to get him to confess what happened. >> reporter: one day, dorine rides down jason's block on her bike and strikes up a conversation with him and his friend. >> new to the neighborhood. i said i was from california, and eventually, i did turn around and started talking to jason aloe, the juror on my son's case. >> reporter: and so you struck up a friendship after that? >> i did. he needed somebody to vent to, and i was there. i was a very good listener. >> reporter: and so you're talking to him the entire time with a recording device strapped to your body. >> yes, yes. >> reporter: and you kept it where? >> between my boobs. he described my son as a tall, skinny kid with glasses and proceeded to tell me how he

hated jews. >> i'm i hate jews. >> and he said he hated jews, believing john was jewish. i wanted to punch him in the face. i wanted to stab him. >> by law, you're not supposed to be. they read you a list of all the witnesses. if you know or affiliate with any of these people in any way you have to let them know. >> i was disgusted with him. because he said it proudly. he committed very serious juror misconduct. and i've uncovered it. >> depends on what he was asked in jury selection. it seems that he knew that he should have said more. in the context of jury selection. did he lie? he says no.

>> dorine doesn't know what to do with the information, so she goes public and tells a reporter from "vanity fair" all about it, and the result is a big feature article. >> reporter: when you saw the pictures of your mom in "vanity fair". >> yeah. >> reporter: dressed up in the way that she dressed up. what was your reaction? >> it didn't even look like her. i didn't recognize her for a second, oh, my god! >> tonight on "nightline." undercover mother. >> this has to be put down on the record. >> was there anything that you felt that was odd or strange about this woman who suddenly becomes a friend of yours? >> she was coming on very strong, very strong. >> do you ever recall saying anything like "i hate jews." >> can you tell me? >> i'm not a prejudice person. >> is it anything you might have said in the past? >> what does that have to do with -- >> just answer the question. >> does it make sense? >> it does.

i'm coming to a point. >> don't answer. >> in one of the tape recordings, you say you hate jews. >> that's your interpretation. >> can you ever remember saying, i shouldn't have been in that jury? >> he doesn't remember saying that, mark. >> do you, jason, ever remember saying that? >> no. >> did you commit perjury? >> absolutely not. >> do you remember anything about the people in that group during that process? >> no. >> reporter: meanwhile, dorine goes back to court with the tapes. >> john juca's file a motion to get a new trial. >> on the grounds of juror misconduct. so the judge denies the motion for two reasons. the jun judge was saying the juror didn't intentionally lie during the process. and secondly, the tape isn't necessarily reliable. >> he says there's no way to

prove they weren't altered. >> he said that you were guilty of extraordinary misconduct. did you go too far? >> um, maybe it was misguided, but definitely not too far, because any mother would do it. >> reporter: so now dorine sets her sights on the star witness, john avee to. she hires a private investigator. >> well, they wanted me to drive and interview him. now it's many years later. let's see who john is now. >> so jathey convinced him to mt in the car and had a tape recorder rolling. >> i just want the truth. >> the whole thing was a lie. the whole thing was a lie. >> he is now coming forward and saying that he made up the story. about juca's confession. and he was the most important witness in the case.

>> jace al peter got john that he was in a mandated drug program, which should have put him into jail, but according to avitto, he had some sort of a deal with the prosecutors. >> and they helped me get out of those to keep me so i could testify. >> at this point, john, john juca's new attorney takes all this information to a judge in an attempt to get their case overturned. the judge's response to this is he grants them a new hearing. >> john avitto comes in. his first words were, apologizing to john. what was your reaction? >> it was like a weight was lifted off my shoulders. >> so the judge listens to all of this and decides that there was no deal. that john avitto's life was not

helped by anything the prosecution did for him. dorine still doesn't give up. >> and then she got an unexpected phone call from her lawyer. >> reporter: in a stunning decision, a panel of four appellate judges overturn her son's conviction. the judges concluded that the prosecutor committed a clear violation of court rules. that they helped avitto. but john remains behind bars because the prosecution has appealed the ruling hoping to get the conviction reinstated. meantime, antonio russo changed his story. >> what he said was he did it alone, that he shot and killed mark fisher. >> i want my name cleared. one of the worst things about this is people thinking i'm a murderer, and i want that wiped away, because it shouldn't be there in the first place.

>> reporter: some people might argue that the fishers deserve closure in this as well. >> and they do, of course they do. >> reporter: and you have empathy for them? >> of course. of course. but in the same respect, i've got to fight for my son's life. you know? i have to fight for my son. >> our thanks to juju. and up next, the two show-stopping finales this weekend. abc news "nightline," sponsored by mercedes benz. how do you gauge the greatness of an suv? is it to carry cargo... or to carry on a legacy? its show of strength... or its sign of intelligence? in crossing harsh terrain... or breaking new ground? this is the mercedes-benz suv family. greatness comes in many forms. visit your local mercedes-benz dealer for exceptional lease and financing offers.

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