The year before, he nearly died from a rattlesnake bite. Debra Bouldin said that experience left him a changed man.

"You know how when people have trauma they either become so thankful about everything about life or else they become bitter against life? Brent went to the bitter side," she said. "That was a very life-changing thing for him. What happened after that, I honestly can't tell you.

She said her prayers were with the trooper's family.

More than 100 federal, state and local law enforcement officers from across southwestern Montana responded to the shooting and authorities closed Highway 2 from the junction of U.S. Highway 287 to Interstate 90 at Three Forks, about 70 miles southeast of Helena.

The Gallatin County Sheriff's Office said Bouldin lived in Three Forks. Public records show he previously lived in Belgrade, a town about 20 miles away.

Belgrade police Sgt. David Keen said a warrant for Bouldin's arrest was issued on Dec. 3, 2009, on a contempt charge, meaning Bouldin either failed to appear in court or did not comply with a court order. Keen said he did not know why the contempt warrant was issued.