Thornton Walmart shooting suspect walked off job, has arrest record dating to 1990

THORNTON, Colo. -- The man suspected of shooting and killing three people at a Walmart store in Thornton on Wednesday night walked off the job that morning and has a history of arrests, and operated two failed businesses, according to federal and state records.

Scott Ostrem walked off his job at B & M Roofing at 9 a.m. Wednesday with no explanation, his boss David Heidt said.

Heidt said Ostream was a sheet metal fabricator at the company since May 2014.

"We’re bewildered," Heidt said, adding Ostream did not seem angry when he left and was always a good employee.

Ostrem’s Colorado arrest record dates back to 1990, when he was arrested by Westminster police on a charge of harassment.

RELATED: Video shows police chase and arrest of Ostrem

He was arrested by the Denver Police Department in 1999 on charges of assault on a peace officer, possession of an illegal weapon, disorderly conduct and resisting arrest.

Most of those charges were later dismissed by the Denver District Attorney’s Office.

He was also cited for driving under the influence by the Adam’s County Sheriff’s Office in 1991 and the Wheat Ridge Police Department in 2013.

Filings with the Colorado Secretary of State’s Office show Ostrem formed Ostrem Installation LLC in June 2012 and the company went delinquent in November 2013.

The records indicate he later opened MKA Electronics LLC in January 2013 before the company went delinquent in June 2014.

According to federal bankruptcy records, Ostrem filed for Chapter 7 bankruptcy in 2015 and at the time, he had more than $58,000 in credit card debt.

Ostrem was sued in 2011 by a man believed to be his father, Ronald Ostream.  The case was closed just a month after it was filed.

Former classmates of Ostrem provided a yearbook photo suggesting Ostrem graduated from Westminster High School in 1988.

The Thornton Police Department said that just after 6 p.m. Wednesday, Ostrem walked into the Walmart store at 9901 Grant St. and and “nonchalantly” began firing with a handgun.

Victor Vasquez, 26 of Denver, and Carlos Moreno, 66 of Thornton, were pronounced dead at the scene. Pamela Marques, 52 of Denver, was taken to a hospital but later was pronounced dead.

On Thursday morning, a SWAT team went into an apartment in unincorporated Adams County that was believed to be connected to Ostrem.

A citizen tip led police to the apartment. The SWAT team went into the apartment at 7121 Samuel Drive but Ostrem was not found.

Just before 8 a.m., the 2017 red, four-door Mitsubishi Mirage associated with Ostrem drove past the apartment complex.

Law enforcement quickly took off and followed the vehicle, stopping it at West 72nd Avenue and Federal Boulevard where Ostrem was apprehended without incident.