carricks. a working-class ire, catholic family with 14 children. brian the 11th. >> parents got married, god, give us as many kids and you want to give us and we'll take them. >> reporter: describe the carrick family for me. >> very nice people. one of the sisters, they didn't have the best clothes, didn't always have school supplies but they had a lot of love. >> reporter: that december 20th was brian's day off, but he went to val's looking for a co-worker passing his brother eddie, also a stockboy on the way. >> eddie was going out to get the carts from the parking lot and brian was walking into the store. he never saw his brother after that. >> reporter: the next day his mother teri received a troubling phone call. brian had not shown up for work. >> she knew her son would never miss work. his life, going to that store. bed. was wrong. >> play for us sinners. >> reporter: with days, disbelief. this was not the kind of town where people just went missing. >> johnsburg is safer and such a smallfamily church-oriented community and then to have just very

carrick family? >> we've lost brian,' we're not going to get him back. the only thing -- the only thing i can hope for is that i'll meet him again some place. >> william carrick died last year in december of 2014, before the court's reversal. other members of the carrick family declined our request for an interview. >> where did he go? people don't disappear. people just don't disappear. that's the part -- that's why it's so unfair to that family that they still don't really know. >> i think what the carrick family needs to do is study the opinion. because the person who committed this crime and the person who helped dispose of brian carrick's body have not been held accountable. and there is nothing that's been gained by having the wrong person locked up. they should push hard to have this case solved and to figure out exactly what happened. the forensic evidence is right there. it tells the story. >> that's my mom. she's the type of person that would hang a baby picture of me in my own room. see in i was cute then. i don't know what happened. >> i wante

rob render's blood was there and his was the only blood ever >> we know that rob render and brian carrick had an altercation because both of their blood is right there at the crime scene. >> for her, the crime scene tells the story. look at these photo exhibits while brian's blood is in the hallway leading to the cooler, rob render's bloody fingerprint is on the cooler door handle. and inside the door, more of rob remembereder's blood. when police questioned rob, he insisted he wasn't there. >> i didn't do anything, i don't know anything. >> they asked rob, if he wasn't there, why was his blood? >> i cut my finger, who knows. maybe i bit my nails so bad because i do that it bled a little bit. >> there's no way that this amount of blood could have been nails. you'd have to be a hemophiliac. disorder. >> and zr zelnar there is motive. brian turned in rob for stealing for being weak. where was rob that night. >> zelnar contends that other employees say that rob was nowhere to be found for two hours but according to rob -- >> i was probably stoned that night. i'm sure. i was 17 years old. tha

and that includes extended family as well. >> brian carrick's family believes that you belong here. >> if allegations are repeated say seven years, you begin to believe that it's a fact. >> the car riks believe that you know where brian's body is. >> it's sad that they think that. it's sad that they would ever think something like that. brian. >> mario says that brian carrick had a good relationship. >> he was a good guy. good family. he worked hard. one of my favorite coworkers. >> his memories of that fateful night are still vivid. just five days before christmas the store packed with shoppers, filling their carts with all of the makings of christmas dinner. it was brian's day off but he showed up that evening around 6:30 asking for another stockboy, robert render. >> and brian was looking for render and asked me if i had seen him, where is this guy. i paged him and that was the last time i seen him. >> after seeing brian, mario nearby, sharing it with employees in a break room. clear across the other side of the store from the produce cooler. that's his alibi. mario says he helped

grisly rumors about brian carrick's murder and the casciaro's involvement had taken hold. >> one of the stories is that brian was killed in the cooler, mario called family from the city who came in, dug him up, dismembered him and threw him in a river in iowa. disgusting rumors that he was cut up in our meat department. then it started becoming that our family was involved in some kind of crime family. >> the fbi investigated and dismissed rumors of a mob hit. this case may have remained an unsolved mystery if not for this man. >> the assistant state's attorney michael combs. >> also known as nick combs. a tough prosecutored determined to find justice for the carrick family. prosecutor combs finds a key witness. his name, shane lamb. >> who is shane lamb? >> shane lamb, he's got a criminal history. he grew u rough. i think he's a very tragic character in all of this. >> a stockboy at val's who worked alongside brian and mario. a five-time felon with a rap sheet that included attempted murder at just 14. anything about brian's disappearance to authorities. now eight years later in jail f

evidence that teenage boy brian carrick was brutally murdered. >> comes up behind him like this and cuts his throat. >> inside a produce cooler. >> a very quick crime scene and then a frantic cleanup. >> what did you think that circular stain was from? >> a tough case with few answers, but many questions. >> well, who did it? everybody was just, like, on edge. >> stock boys with a past. >> i didn't do anything, and i don't know anything. it's like -- >> a dogged prosecutor with his sights set on one man. >> this is assistant state's attorney. >> and this blood-iffing crusader, equally determined to find the real killer. >> never should have been charged with this. a colossal failure on the part of the system. >> tonight, the shocking reason this man is now home for the new year. >> my baby. >> and how "20/20" played a role in getting him there. >> the mystery on johnsburg