Tom Decker, Minn. police officer and father of four, fatally shot while conducting welfare check

(CBS/AP) COLD SPRING, Minn. - A 31-year-old police officer with four children was shot to death late Thursday while performing a welfare check. Authorities are calling the incident an ambush killing.

Officer Tom Decker was responding to a report of a suicidal man when he was shot twice after getting out of his squad car near an apartment behind a downtown bar. He died at the scene.

Ryan Michael Larson, 34, of Cold Springs, was arrested and booked into the Stearns county jail on murder charges early Friday morning.

Stearns County Sheriff John Sanner said his department got a call Thursday at around 9 p.m. from Larson's family members saying that he might be suicidal. Cold Spring police went to his home once and couldn't find anyone, then returned almost two hours later.

It was on the second trip that Decker, a six-year veteran of the force, was shot. He was wearing a bulletproof vest.

"It's apparent to us the officer was ambushed at the scene," Drew Evans, assistant superintendent of the state Bureau of Criminal Apprehension, said.

Police with dogs searched Friday for a gun near the site of the shooting. Brien Moen, who lives about a block from the crime scene, said officers who came to his door told him they were looking for a sawed-off shotgun.

Larson has been in trouble with the law before, mostly for traffic-related offenses, and once in an abuse case.

Decker, who was called "a chief's dream," by Cold Springs Police Chief Phil Jones, leaves behind a wife and four young children.