CHICAGO (AP) -- Special prosecutors investigating allegations that police tortured black suspects in the 1970s and '80s said Wednesday they found evidence of mistreatment, but any crimes are now too old to prosecute.
"It is our judgment that the evidence in those cases would be sufficient to establish guilt beyond a reasonable doubt," Robert D. Boyle and Edward J. Egan wrote in a long-awaited report.
Their four-year investigation focused on allegations that detectives under the command of Lt. Jon Burge beat suspects, used electric shock on them, played mock Russian roulette and started to smother at least one man to elicit confessions.
No one has ever been charged, but Burge was fired after a police board found he had abused a suspect in custody. His attorney has said Burge never tortured anyone.
Boyle and Egan investigated cases based on the complaints.
"Regrettably, we have concluded that the statute of limitations would bar any prosecution of any offenses our investigation has disclosed," they said.
Several people who claimed to have been abused or tortured by Chicago detectives have filed civil lawsuits, however, and the report could bolster their legal claims.
The allegations also have drawn attention from human rights groups.
In May, a United Nations anti-torture panel said the Chicago investigation needs to go farther than it has. They said the United States should ensure that law enforcement officials who mistreat suspects are punished.