CHICAGO (AP) — Authorities in Illinois and Indiana searched Friday for a convicted murderer who was mistakenly released from custody in Chicago, with the two sides differing over whether a paperwork error could be to blame.

Steven L. Robbins, 44, was released Wednesday evening from a jail in Chicago, where he had been taken to answer to drug and armed violence charges in Cook County Circuit Court. Those charges were dropped, and Robbins was freed instead of being sent back to Indiana to continue serving a 60-year murder sentence. The public was not alerted that a potentially dangerous convict was on the loose until about 24 hours later.

Indiana Department of Corrections said in a news release that "for reasons yet unknown, the offender was released by Illinois authorities without being held for return."

The department submitted paperwork telling Illinois officials that Robbins was supposed to be returned to Indiana, spokesman Douglas Garrison said Friday.

"It's quite clear that all of the paperwork from IDOC was in order, so that they would have known that he was supposed to be returned to us," Garrison said.

The Cook County Sheriff's Office said it was investigating how Robbins was released. Sheriff's office spokesman Frank Bilecki told the Chicago Sun-Times that an initial investigation showed there was no paperwork indicating Robbins should be held.

Bilecki did not respond to requests for comment Friday.

Robbins, a Gary, Ind., native, was serving the decades-long sentence for murder and weapons convictions out of Marion County in Indiana.

Witnesses to the 2002 killing told police at the time that Robbins was arguing with his wife outside a birthday party in Indianapolis when a man intervened, telling Robbins that he should not hit a woman, according to court documents. The witnesses said Robbins then retrieved a gun from a car and shot the man, Rutland Melton, in the chest before fleeing.

Robbins was also found guilty of carrying a handgun without a license.

He started serving his sentence in October 2004 and his earliest projected release date was more than 16 years from now, on June 29, 2029.

Illinois and Indiana have issued arrest warrants for Robbins and officials in both states are asking for the public's help to apprehend him.

It is not the first time a prisoner has been mistakenly freed from the Cook County Jail.

In 2009, Jonathan Cooper, who was serving a 30-year manslaughter sentence in Mississippi, was brought to Chicago to face charges that he failed to register as a sex offender.

Prosecutors dropped the charges because, as an inmate, he could not comply with the Sex Offender Registration Act.

A clerk reportedly failed to include the Mississippi sentence information in Cooper's file, and jail staff released him.

Cooper turned himself in several days later.

In a more recent embarrassment for law enforcement officials in Chicago, two convicted bank robbers escaped from a high-rise federal lockup in December by climbing down the side of the building on a rope made of bed sheets and jumping into a cab. Authorities recaptured both men, one of whom remained on the run for about two weeks. Officials have yet to provide a public explanation of the jailbreak and what security lapses allowed it to happen.