CLINTON, Mo. (AP) — Investigators say they have found a rifle believed to have been used in last weekend’s shooting death of a western Missouri police officer.

Missouri State Highway Patrol Sgt. Bill Lowe says the unspecified gun was found Thursday in a creek about two miles north of Clinton, where 37-year-old officer Gary Michael was shot and killed Sunday night.

Lowe says he couldn’t immediately specify the style of the rifle or how investigators came to find it.

A suspect in Michael’s death, 39-year-old Ian McCarthy, was arrested late Tuesday after a two-day manhunt and is charged with first-degree murder and armed criminal action.

McCarthy’s public defender, Alice Wasson, told The Associated Press that a not guilty plea will be entered on McCarthy’s behalf during a court appearance Friday.