Eric Caine, who has for years claimed he was tortured by Chicago police into confessing to a double murder has been ordered released from prison after more than 20 years. (AP Photo/Illinois Department of Corrections)

CHESTER, Ill. (AP) — A man who for years claimed police tortured him into confessing to killing a Chicago couple a quarter century ago walked out of prison Thursday, eight years after his co-defendant was pardoned and freed from the state's death row by the then-governor.

Eric Caine's release from southwestern Illinois' Menard Correctional Center followed a judge's dismissal Wednesday of charges that landed Caine a life sentence. Cook County Judge William H. Hooks' ruling came the same day a former Chicago police commander Caine had accused of threatening him with a gun reported to a North Carolina federal prison to begin serving a 4 1/2-year sentence for lying about the torture of suspects.

"It was a surprise that this order dismissing the charges came down the way it did," Caine's attorney, Russell Ainsworth, said Thursday outside the brown stone prison along the Mississippi River, about 60 miles southeast of St. Louis.

Caine, 45, and co-defendant Aaron Patterson had claimed then-Chicago police Lt. Jon Burge and officers under him coerced them into implicating themselves in the 1986 killings of the elderly couple found stabbed 34 times.

Patterson was sentenced to death but was pardoned with three other men on the state's death row in 2003 by then-Gov. George Ryan after the Republican said he had concluded that Patterson's confession was coerced. All four inmates made similar torture claims and years after being pardoned reached a $20 million settlement with the city.

But until Thursday, Caine languished in prison as he pressed to get his case re-examined.

Hooks ruled in January that Caine was entitled to a post-conviction hearing based on his allegations of torture, and prosecutors decided to drop the case rather than proceed, said Stuart Nudelman, a former judge acting as the special prosecutor in Caine's case.

"We were left with, at this point, a questionable confession and really no other evidence," Nudelman said, adding that during any retrial it was unlikely prosecutors would not have been able to meet their burden of proving Caine's guilt.

Patterson, 46, is now serving a 30-year sentence at a federal prison in central Pennsylvania after being accused of dealing drugs as a ranking street gang leader.