Updated

A 34-year-old man accused in the fatal shooting of a police officer in a small central Minnesota city was released from custody Tuesday after authorities determined they did not have enough evidence to file charges.

The investigation into the killing of 31-year-old Officer Tom Decker in Cold Spring continues, and authorities were still looking for the 20-gauge shotgun that is believed to be the murder weapon, officials said.

Authorities at the Stearns County jail confirmed that Ryan Michael Larson was released shortly before noon Tuesday. The Bureau of Criminal Apprehension and the Stearns County Sheriff's Office said in a news release that prosecutors did not have "sufficient documented evidence" to continue to hold Larson on suspicion of second-degree murder charges at this time.

"Our agencies have reviewed the investigative data collected thus far and must act within the time allotted by law, within the constraints of the law, and based on the facts known at this time," Stearns County Attorney Janelle Kendall said in a statement.

Decker was shot near a bar in downtown Cold Spring as he and his partner were checking on a man who was reported to be suicidal. Authorities have described the shooting as an ambush. Cold Springs is about 75 miles northwest of Minneapolis.

Decker, a father of four, had been with the Cold Spring department for six years. He grew up on a farm just south of Cold Spring, a city of about 4,000 residents. After graduating from college he worked at several small Minnesota police departments before coming home for what he called his dream job on a force with only eight full-time officers.

Cold Spring Police Chief Phil Jones said last week that Decker had received repeated letters of commendation and appreciation.

A visitation for Decker was being held Tuesday evening. Officials estimate up to 2,000 officers from around the country could attend his funeral Wednesday in nearby Collegeville.

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