Markus Kaarma's legal defense team is probing the training of the Missoula Police Department.
NBC Montana obtained a copy of a subpoena, filed by Kaarma's attorneys, requesting copies of training manuals and training records of 13 officers involved in the investigation.
Kaarma admits he shot German foreign exchange student Dieren Dede after surveillance cameras spotted Dede in the garage of Kaarma's Grant Creek home.
He claims he was concerned for his safety and the safety of his family.
Kaarma's trial is scheduled for December.