(CBS) —The Cook County sheriff’s office says a 29-year-old Chicago man who had been in custody for shooting and killing a driver on the Dan Ryan Expressway almost five years ago was mistakenly freed three days ago by the state of Illinois.

Prosecutors say it was September of 2012 when Garrett Glover of Chicago fired at a Jeep on the Dan Ryan and killed the 25-year-old driver.

Garrett Glover (Cook County Sheriff's Department)

Garrett Glover (Cook County Sheriff’s Department)

Glover was charged with murder in 2015.

Before he’d been charged with that, Glover was charged with attempted armed robbery in another case.

He was sentenced last Thursday on the armed robbery case and taken to Joliet for processing.

The Illinois Department of Corrections figured Glover already had enough credit for time-served in Cook County, says Cara Smith, the sheriff’s chief policy officer.

But she says that instead of returning Glover to Cook County Jail to face the murder charges, IDOC set him free.

“They were apparently unaware of the open murder case and therefore permitted his release,” Smith tells WBBM’s Steve Miller.

It’s not clear who is at fault.

The state Department of Corrections appeared to try to deflect blame, saying, “The Department did not receive any additional documentation or information indicating (Glover) should be held beyond his February 24th, 2017 release date.”

Smith says the most important thing is to find Glover. Anyone who can help is asked to call (774) 674-0169.

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