THORNTON, Colo. (AP) — Police have released very little information about a man who abruptly left his job hours before allegedly shooting three people to death inside a Thornton Walmart, but neighbors described him as loner who often seemed angry.

Scott Ostrem (credit: Thornton Police)

Scott Ostrem, 47, was arrested following a brief chase Thursday, a day after the shooting. Killed were Pamela Marques, 52, of Denver; Carlos Moreno, 66, of Thornton; and Victor Vasquez, 26, of Denver.

Police have not said if they know a motive for the shooting.

Residents of the Samuel Park Apartments building where Ostrem lived described him as a rude man who kept to himself.

“He didn’t seem to have anybody,” said Teresa Muniz, one of his neighbors. “Being angry all the time. That’s what he seemed like, always angry.”

“We didn’t even know his name ’til today,” she said.

Muniz said most of the building’s tenants talk to each other, but Ostrem never returned her greetings and swore at people for leaving laundry in communal machines. She also said she sometimes saw Ostrem carrying a shotgun or a bow and set of arrows to and from the building, which faces the back side of a liquor store, a dollar store and a cellphone store.

Another neighbor, Gerald Burnett, a 63-year-old retiree who lives in a first-floor unit, said he was sitting on the stairs drinking coffee one morning when Ostrem came down, told him to move and cursed at him.

“Dude had an attitude, big time,” Burnett said. “He’s the type of person if you said ‘good morning,’ he wouldn’t say nothing.”

A maintenance worker at the apartment building had a similar story about Ostrem, who is set to appear in court Friday.

“He’ll basically just tell you f-off if you tell him ‘hi.’ Good morning, he’ll tell you f-off,” said Dennis Valenzuela, adding that it didn’t appear that Ostrem had a girlfriend or any friends.

“Just a single man. He didn’t want anything to do with anybody,” Valenzuela said.

A Facebook profile that appears to belong to Ostrem lists only one friend, a woman who is from Thornton and who has since moved to Florida.

Little else is publicly known about Ostrem, who police say nonchalantly walked into the Walmart and opened fire, sending dozens of shoppers and workers fleeing in a panic from the busy store.

The morning of the shooting, he left his work station without any explanation and never came back, said David Heidt, his boss at B&M Roofing.

Heidt said Ostrem worked in the company’s metal fabrication shop for the last three years without any problems, and he was a good and quiet worker who was skilled at his craft of making metal flashing for roofs.

“We’re all bewildered as to where we are now,” Heidt said.

Ostrem recently ran into financial problems.

In September 2015, Ostrem filed for Chapter 7 bankruptcy and listed his income for the previous year as $47,028. He estimated that he owed more than $85,000 including credit card debt and said he worked as a sheet metal fabricator at a roofing company in the town of Erie, about 25 miles (45 kilometers) north of Denver.

Ostrem had worked for a Denver roofing company until 2014, said Sandra Runyon, an administrative assistant at Tecta America Colorado Commercial Roofing. Runyon said the company had had no contact with Ostrem since he left.

There was no evidence Ostrem had ever worked for Walmart, spokesman Ragan Dickens said.

Ostrem had minor run-ins with police dating back to the 1990s, including a December 1999 charge of resisting arrest in Denver that was dismissed the following year.

He bounced from job to job and has been tied to at least 11 street addresses, including six apartments, in the Denver metro area since 1991.

By P. SOLOMON BANDA and KATHLEEN FOODY, Associated Press … Associated Press writers Tatiana Flowers, Nicholas Riccardi, Thomas Peipert, Dan Elliott and Colleen Slevin contributed to this report.

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