Karl Smith took the witness stand at the Leighton Criminal Court Building in Chicago on Thursday and made a confession that stunned those present.
Smith admitted to committing a 2003 murder for which his identical twin, Kevin Dugar, was put behind bars.
"I'm here to confess to a crime I committed that he was wrongly accused of," Smith testified, according to the Chicago Tribune.
Despite the confession, prosecutors are skeptical, noting that Smith is currently serving a 99-year prison sentence for his participation in a 2008 home invasion and armed robbery in which a 6-year-old boy was shot in the head. Smith, the Tribune reports, only came forward with his admission after an appeals court upheld his conviction for attempted murder.
"He's got nothing to lose," Assistant State's Attorney Carol Rogala said, telling Judge Vincent Gaughan that Smith's confession didn't "fit the independent eyewitness accounts of what happened."
According to the Tribune, the two brothers look so alike that even on Thursday they were distinguished only by their prison clothes. The brothers have different last names because Smith adopted their mother's maiden name.
Growing up, they dressed alike until eighth grade and regularly impersonated each other for years afterward. According to the brothers' mother and Smith, they were so close growing up, they were "one person" who shared socks, shoes and sandwiches.
As they got older, Smith admitted, Smith and his brother were gang members who dealt drugs.
"We was acting as one," Smith testified. "Where I was, he was, acting like each other. He pretended to be me, and I pretended to be him."
In the 2003 murder for which Smith is now taking the blame, a gunman dressed in black shot into a group of three people, killing Antwan Carter.
Dugar was convicted of first-degree murder in 2005 and sentenced to 54 years in prison. Smith first confessed to the murder in a letter he wrote to his brother three years ago.
"I have to get it off my chest before it kills me," Smith wrote, according to the Tribune. "So I'll just come clean and pray you can forgive me. … I'm the one who and shot and killed those two Black Stones on Sheridan that night."
When Dugar didn't answer, Smith wrote again a few weeks later, confessing again and pleading with his brother for forgiveness.
"The reason I didn't say [expletive] at the time was because I didn't and couldn't find the strength to do so at the time," Smith wrote, according to the Tribune.
Dugar wrote back and asked Smith to contact his lawyers. Smith signed a sworn statement confessing to the homicide in 2014.
If a judge believes Smith's story, his brother would face a new trial for the 13-year-old murder.
At least one person believes the brothers.
"I hope Kevin will get out. I hope he change his whole life around," the brothers' mother, Judy Dugar, told the Tribune. "He got to."
"[Karl] wouldn't lie about that," she added.
Read more at the Chicago Tribune.