POST, Oregon -- A 72-year-old man charged with killing his son told investigators the gun "went off" after his son hit him in the face with an open backhand.

William Brown Sr. was arrested on a murder charge last week at his home in Post, southeast of Prineville.

Crook County Deputy Dave Tugman wrote in court documents released Monday that 51-year-old William Brown Jr. was dead when deputies arrived.

According to Tugman, the elder Brown said he was trying to get his son to move back to Minnesota and pulled the gun to threaten him. The father said the son's backhand caused his head to hit a doorjamb, and the gun fired.

A medical examiner said Brown died from a gunshot that entered near the left armpit and exited near the right armpit.

-- The Associated Press