Several guns were found, according to the Bureau of Criminal Apprehension, but the agency was searching for additional weapons that may be related to Decker's death. Brian Moen, who lives about a block from the bar, said officers who came to his door told him they were looking for a sawed-off shotgun.
Cold Spring Police Chief Phil Jones said Decker was the "department jokester" on a force with only eight full-time officers. Decker served as the department's instructor on firearms and use of force. Jones said he never had problems with Decker, noting he'd received repeated letters of commendation and appreciation.
Decker leaves behind a wife and four children from a previous marriage — two daughters ages 8 and 7, and two sons ages 6 and 5.
His younger brother, Joe Decker, told The Associated Press that his brother loved to travel and be outdoors. He said his brother was shy and reserved as a youngster but became outgoing and gregarious as an adult.
"He was one of those people who'd be the life of the party," Joe Decker said.
Police attention had been drawn before to Larson, a machine tool student at St. Cloud Technical and Community College, though mostly for traffic-related offenses but once in an abuse case.
In 2009, he reached a plea agreement to settle a misdemeanor disorderly conduct charge for engaging in behavior that could "arouse alarm, anger, or resentment in others." As part of the plea deal, he served a day in jail and agreed to undergo domestic abuse counseling. A no-contact order was issued. Court files indicated he violated his probation in 2010.
"He's a normal person," Jeff Scoles Jr., a friend of Larson's, told the AP late Friday. "He's not a monster."
Scoles said Larson lived in an apartment above his bar and has filled in as a bartender at another bar he owns. Scoles added that Larson was doing his homework at one of the bars Thursday and was in a "good mood" when he left that afternoon.
He added that Larson took a concealed-carry class in January and that Larson owned guns, but "was cautious with them."
Condolences for Decker came from fellow police officers in other Minnesota departments and from elected officials, including Gov. Mark Dayton.
"On behalf of the people of Minnesota, I extend my deepest sympathies to his family and to the Cold Springs Police Department for their tragic loss of an outstanding officer, father and friend," the governor said.
Associated Press writers Brian Bakst in St. Paul, Minn., Dinesh Ramde in Milwaukee and Jeff Baenen in Minneapolis contributed to this report.