-- intro:In the small town of Johnsburg, Illinois, a 12-year-old unsolved mystery still has people talking.
Brian Carrick was a likable 17-year-old high school junior. One Friday night, he vanished from inside Val’s Foods, the grocery store where he worked just five days before Christmas 2002.
Within days, Johnsburg was in disbelief not knowing whether Carrick was dead or alive.
Casciaro is serving a 26-year prison sentence for the crime he said he didn't commit.
Click through to go inside the case of what happened to Brian Carrick and for a closer look at the key players and evidence.
Known to some as the “Mayberry of the Midwest,” the town is so quiet that a murder has never been recorded in its history.
“Murders don’t happen here. You know, you got people getting stopped by the cops for speeding or DUI, but certainly nothing to that level,” Johnsburg head librarian Maria Zawacki told ABC News’ “20/20.” media:25846575
quicklist:2 title:The Carrick Family text:Brian Carrick lived in Johnsburg with his family. Carrick was the 11th child of 14 in his Irish Catholic family.
Carrick was a stock boy at Val’s Foods, Johnsburg’s only grocery store, which was across the street from the Carricks’ home on Johnsburg Road.
“He's that type of guy, felt like he owned the place himself, you know?” former Val’s Foods manager Eugene Casciaro, whose father was one of the owners, told “20/20.” “I mean, he'd come in and start bagging groceries on his days off if he [saw] that a line was backed up.”
Val’s Foods co-owner Jerry Casciaro said Carrick was like a son to him.
“You have no idea how smart he was. If you tell him to do one thing one time ... Next time he’ll tell you what to do,” Jerry Casciaro told “20/20.” media:25869111 caption:use
quicklist:3 title:The Casciaro Family text:The Carricks and the Casciaros were two of Johnsburg's best-known families.
The families were friendly for nearly 20 years. Almost half of the Carrick’s children had worked at Val’s Foods.
“I think like eight of them worked at the store. They used to love coming into the store because my father used to measure them when they came in,” Julia Muell, one of Jerry Casciaro's daughters, told “20/20.”
Italian immigrants Jerry and Maria Casciaro met and married in the United States, realizing their American dream when they joined with relatives to buy Val’s Foods.
Mario Casciaro, then 19, was the youngest of Jerry Casciaro's four children and was planning to take over the family business. He was a stock boy like Carrick and was working a shift on the day he vanished.
“Mario is full of life. You never see him having a bad day,” Mario Casciaro's sister Joanne Casciaro told “20/20.” “You never hear him talking bad about anybody. He makes the most out of every day.” media:25843882 caption:use
quicklist:4 title:Brian Carrick Goes Missing text:Dec. 20, 2002 was Brian Carrick's day off, but that evening, he went to Val's Foods, passing his brother Eddie Carrick, also a stock boy, on the way inside.
The next day, Carrick's mother Terry Carrick received a phone call that her son hadn't shown up for work. Within days, Johnsburg was reeling, searching for the missing teen.
The tight-knit community rushed to support each other. Val’s Foods posted a $25,000 reward and helped with a candlelight vigil outside the store.
Police later found blood evidence belonging to Carrick. They also found a bloody fingerprint on the door handle of the produce cooler inside the store.
As the investigation intensified, authorities were convinced that Carrick was killed over a drug debt he owed Casciaro. But with no witnesses or physical evidence linking Casciaro to the crime scene, the investigation grew cold. media:25952379 caption:use
quicklist:5 title:An Unexpected Witness Comes Forward text:Three years after Brian Carrick's disappearance, Mario Casciaro went on to graduate from Illinois State University with a degree in finance.
But in 2007, he was arrested and charged with perjury. Prosecutors said he lied to the grand jury about not knowing how Carrick was killed and how his body was disposed. He was acquitted of the charge in 2009.
Prosecutors got a new break in the case when they found key witness Shane Lamb.
Lamb had been a stock boy at Val’s Foods, working alongside Carrick and Casciaro. He was a five-time felon with a record that included attempted murder when he was just 14.
Facing 12 years in prison on cocaine charges, Lamb, who had for years denied knowing anything about Carrick’s disappearance, told prosecutors in 2010 that he was ready to make a deal.
After being given immunity from any charges related to Carrick's death and a reduced sentence on the cocaine conviction, Lamb told authorities Casciaro was behind it all, as seen in this 2010 videotaped meeting obtained by ABC News. According to Lamb, Casciaro wanted him to intimidate Carrick into paying back drug money he owed.
Lamb told prosecutors that on Dec. 20, 2002, he left a party and went to the store where he found Mario Casciaro, who told him Brian Carrick was in the produce section. media:25897870 caption:use
quicklist:6 title:Shane Lamb Claims He Confronted Carrick text:During his 2010 meeting with prosecutors, Shane Lamb said he yelled at Brian Carrick by the produce section.
"I went over there, told Brian, 'What's up with the money you owe him? Why don't you pay him, you know, at least some of the money back?'" Lamb said to police during his interrogation.
Lamb said that when they became too loud, Mario Casciaro told them to go inside the produce cooler, seen here in this police evidence photo. media:25846317
quicklist:7 title:Inside the Produce Cooler text:While inside the Val's Foods producer cooler, Shane Lamb told prosecutors in 2010 he knocked Brian Carrick unconscious.
Uncertain if Brian Carrick was dead or alive, Lamb claimed Mario Casciaro told him to leave and that he would handle it.
Early in the case of Carrick's disappearance, investigators found blood identified as Carrick's in and around the grocery store produce cooler. There were also signs of a violent struggle.
Blood on boxes found inside the produce cooler can be seen here in this police evidence photo. media:25846130
quicklist:8 title:Mario Casciaro Found Guilty text:On Feb. 25, 2010, just months after being acquitted of perjury, Mario Casciaro was arrested and charged with first degree murder with intimidation and unlawful restraint in the death of Brian Carrick.
According to prosecutors, Casciaro was legally responsible for Shane Lamb’s actions the night Brian Carrick was last seen. Mario Casciaro pleaded not guilty, but Lamb became the prosecution's star witness.
On Feb. 1, 2012, after 12 hours of deliberation, the jury was deadlocked eleven to one in favor of the prosecution. A mistrial was declared.
Prosecutors brought a second trial against Casciaro for the charge of first degree murder with intimidation on March 25, 2013, and again Lamb testified against him. Jurors convicted then-29-year-old Casciaro on April 2, 2013. He was sentenced to 26 years in prison. media:25868790 caption:use
quicklist:9 title:Mario Casciaro Maintains His Innocence text:With credit for nearly two years served in jail, Mario Casciaro, now 31, will be 54 when he is released from prison.
The prosecution, according to Casciaro, was overzealous with its desperate attempt to hold someone accountable for Carrick’s death.
“They're not interested in the truth 'cause if they were, I wouldn't be sitting here. They just wanted a conviction,” Casciaro told “20/20.”
“I sit every day in a five by ten concrete box thinking ... ‘How did this happen?’” said Casciaro.
In an exclusive interview with ABC News’ “20/20” this week, Shane Lamb recanted his testimony, saying he lied to prosecutors and lied under oath.
“All of it was false. Every single thing... The state’s attorney set it up,” Lamb told “20/20.” “Mario is in there for 26 years for something he didn’t do.”
Although they denied a request for an interview citing the ongoing case, the McHenry County state's attorney's office provided a statement to "20/20" about Lamb's recantation: "Shane Lamb gave a videotaped, recorded account of the incident as it occurred in Johnsburg the day Brian Carrick disappeared. He gave a videotaped recording in the State’s Attorney’s Office, with the advice and counsel of his attorney and in his attorney’s presence on January 20, 2010. He consistently repeated the same account of the events at two subsequent jury trials." media:25843650
quicklist:10 title:Where Is Brian Carrick? text:Brian Carrick’s body has never been found and he is still considered a missing person.
His mother, Terry Carrick, died in 2009 never knowing what happened to her son.
Brian Carrick’s father Bill Carrick, pictured here, still lives across the street from Val’s Foods, having to look at where his son vanished every single day.
The Carrick family, their attorneys and the Johnsburg Village Police Department declined ABC News’ requests for an interview or comment for this story.
How long will the Carrick family have to wait for answers? Could new evidence and a recantation of a key witness overturn Mario Casciaro’s conviction and set him free? media:25867821