The only suspect arrested in the fatal shooting of Cold Spring police officer Tom Decker was released from jail Tuesday, just hours before Decker's fellow officers and other mourners began filing into a Cold Spring church for his visitation.

On Wednesday, those officers will confront two daunting jobs -- burying their fallen colleague and identifying his killer.

Ryan Michael Larson, the reportedly suicidal man Decker and his partner were sent to check on Thursday night, was released after investigators concluded they didn't have enough evidence to charge him in Decker's death.

"Some of these are close calls; this one is not," Stearns County Attorney Janelle Kendall said, explaining her decision to cut Larson loose.

In a jailhouse interview with the St. Cloud Times before he was released, Larson, 34, maintained he was innocent.

Late Tuesday, however, Jill Olivera, a spokeswoman for the Minnesota Bureau of Criminal Apprehension, said that Larson remains a suspect. Investigators, she said, are pursuing many leads and continue to search for the 20-gauge shotgun used to shoot Decker behind Winners bar in Cold Spring late Thursday. The team of investigators attempting to crack the slaying has doubled.

"Obviously we are still looking for that weapon," BCA Assistant Superintendent Drew Evans said. "We will continue to search for it. We've been in the river, we've had divers down, we've had submersibles down as well, but searching a river is an inexact science."

Decker, a 31-year-old father of four young children, was responding to a welfare check when he was shot. He was wearing a protective vest, but witnesses said he was shot in the face in the alley behind the bar. Within an hour, authorities arrested Larson, who occasionally tends bar and lives in an apartment upstairs.

It's believed he left jail with family members. A bartender at Winners said Larson hadn't returned to his apartment and probably was with family members in the Twin Cities.

She said police spent much of the day Monday in and around the building, apparently searching and trying to collect additional evidence.

"They left a mess up there," said the bartender, who declined to give her name.

Police evidence tape still clung to the apartment door atop a flight of wooden stairs at the rear of the building. No one answered a knock on the door.

In a 10-minute phone interview Sunday from jail, he told the St. Cloud Times that police had no evidence against him.

"They have no gun, they have no fingerprints, they have nothing."

Larson gave his account of his full day on Thursday, until he went to sleep about 8:15. He said a text he sent to family members about a "big day" Friday was misinterpreted.

Larson's family members called police about 9 p.m., asking officers to check on him because they said he had been sending text messages threatening to kill himself.

"I did send a couple text messages to my parents letting them know that [Friday] was a big day," Larson told the paper. Larson said the messages were meant to indicate that he'd be taking a new direction at school -- St. Cloud Technical & Community College.

Officers got no response in their first attempt to contact Larson. Decker and another officer returned about 10:45 p.m. and were ambushed behind Winners bar, authorities said.

Larson insists he was sleeping at the time of the shooting.

"The next inkling I had that anything was going on out there was when search teams were coming down my hallway," Larson told the Times.

Jeff Scoles, who with his parents owns Winners, told the Star Tribune Friday night that Larson had spent a good part of the day with him Thursday.

"He was normal," said Scoles, who grew up in the same town as Larson -- St. Joseph -- and considered him a friend. "In fact, I thought he seemed like he was in a good mood."

'With love and honor'

Hundreds of mourners, including uniformed law enforcement officers from Minneapolis, St. Paul and many Twin Cities suburbs, waited in chilly night air as a line snaked into the fallen officer's visitation at St. Boniface Catholic Church in Cold Spring.

Across the street from the church, Tim Leyendecker stood on his darkened front porch and watched the line of mourners as they waited to enter the church. Decker, a onetime K-9 officer, stopped by on occasion to play with Leyendecker's German shepherd.

"It's pretty hard to deal with ... it's hard. Especially on those kids. I can't imagine," Leyendecker said. "He was a good cop around here. He was well-liked by everybody that I know."

Like several other mourners, Leyendecker said Larson's release on Tuesday has only made things harder, adding that it's too early to know if they had the right man.

Collages of photos and treasured keepsakes lined the walls of the church, reflecting a young family man's life with his new wife: mugging with her at a bar, dancing with his four kids at his wedding, or grinning in uniform, looking barely older than a teenager as he posed with a family member early in his career. In a hollowed-out old business directory were the words "Marry Me Alicia" next to a flower and a ring from his proposal.

The line led to the front of the church, where Decker lay in his Cold Spring police uniform below the words "With Love and Honor" along with his badge number, 6402. Next to the casket, flanked by a rotation of Decker's white-gloved fellow officers, sat his wife, Alicia, wrapped in a Cold Spring police leather jacket.

James Glynn, Alicia's uncle, said his family was comforted by having so many visitors.

"We all need each other to get through times like this," Glynn said. "It's a tough one. It's going to take some time."

Decker's funeral is at 11 a.m. in St. John's Abbey in Collegeville.

Staff writers Curt Brown and Mary Lynn Smith contributed to this report. 612-673-1751 612-673-4921