Ralph Jeremias was convicted of conspiracy to commit robbery, burglary while in possession of a deadly weapon, two counts of robbery with the use of a deadly weapon, and two counts of murder with the use of a deadly weapon. The charges stemmed from a conspiracy to rob Brian Hudson and Paul Stephens that resulted in the two men being murdered in their apartment. A jury sentenced Jeremias to death for the murder convictions. Jeremias then obtained relief from the judgment of conviction and death sentences when the district court granted in part his postconviction petition for a writ of habeas corpus. The primary issue in this appeal is whether the district court erred in granting relief on Jeremias' claim that trial counsel should have pursued testimony to impeach the testifying codefendant.