By Keith Coffman

DENVER (Reuters) - A Colorado mother and her two small sons who were reported missing after she failed to return home after picking them up at a local school were found dead inside the family’s minivan on Wednesday morning, police said.

The bodies of Jennifer Marie Laber, 36, and her sons Adam, 3, and Ethan, 5, were discovered in the vehicle that was parked outside a shuttered sports equipment store, the Douglas County Sheriff’s Office said in a statement.

The trio was reported missing Tuesday night by Ryan Laber, Jennifer Laber’s husband and the boys' father, after the three victims did not show up at the family home in the Denver suburb of Highlands Ranch, police said.

Steve Johnson, chief deputy for the sheriff’s office, told reporters that Ryan Laber has cooperated with detectives, is not considered a suspect in the deaths, and that there is no threat to the community.

Johnson did not disclose how investigators believe they died.

"We do not have a lot of answers,” Johnson said, adding that there was no indication that the family was in any danger beforehand. "We certainly did not see this horrific ending."

Laber was captured on a surveillance camera Tuesday leaving the boys’ school with her sons before classes had let out for the day, police said.

After receiving the report Tuesday night, police issued a missing persons alert with photographs of Laber and the two boys, along with a description of the 2011 silver Chrysler Town & Country minivan that she was driving.

Around 7:45 a.m. Wednesday, a person called police to report seeing the vehicle parked at the loading dock at a closed sports store in the city of Lone Tree, police spokesman Sergeant Tim Beals told Reuters.

Beals said the person reported seeing an “unknown trouble” inside the van and police converged on the scene, and later identified the bodies as the missing boys and their mother.

The cause of deaths will be released later on Wednesday, Beals said, but declined to say if the case was being investigated as a murder-suicide.

(Reporting by Keith Coffman in Denver; Editing by Dan Whitcomb and Bill Rigby)