Drew Peterson's attorneys rested their case after calling three inmates to testify in the former suburban Chicago police officer's murder-for-hire trial.

The Chicago Tribune reports that the inmates testified Friday that the prosecution's star witness is untruthful and a scam artist. Peterson is accused of trying to hire someone while in prison to kill former Will County State's Attorney James Glasgow, who helped convict Peterson in 2012 of killing Peterson's third wife, Kathleen Savio, eight years earlier.

Peterson is serving a 38-year sentence, but could get another 60 years if he's convicted in the murder-for-hire case.

Among the evidence prosecutors presented were secret recordings of Peterson talking with a prison informant. Peterson's attorney tried to discredit the recordings as unintelligible conversations recorded by a snitch.

Closing arguments are scheduled for Tuesday.