The initial warrant for the 47-year-old Ostrem’s arrest carried three charges of first-degree murder after deliberation, but his formal charges have yet to be filed, according to court records. The affidavit in the case remained sealed early Friday, but could be unsealed later in the day.
Denver7 will have reporters in court for Ostrem’s 11 a.m. appearance and will stream his hearing live.
Police arrested Ostrem near 72nd Ave. and Federal Thursday morning more than 12 hours after the shooting occurred. An anonymous citizen tip alerted authorities to his presence in the area, police said, though FBI agents also spotted him in the area. Ostrem was arrested just a few blocks from his apartment.
The coroner for Adams and Broomfield counties on Thursday identified the three killed in the shooting as 52-year-old Pamela Marques of Denver, 66-year-old Carlos Moreno of Thornton, and 26-year-old Victor Vasquez of Denver.
GoFundMe pages can be found for each of the victims at the following links: Marques; Moreno; Vasquez.
The Thornton Police Department and FBI are leading the state and federal investigations, but both said Thursday they had yet to determine a motive for the shooting.
Officers described “mass chaos” at the scene, and at a Thursday morning press conference, an officer said that some concealed-carry owners had to be detained because they also pulled out their weapons at the store.
A Thornton police spokesman told Denver7 officers had to take extra time detaining some people who had guns and were concealed-carry license holders. Those people were vetted and let go.
Moreno and Vasquez were found dead at the scene near the store’s south entrance. Marques died after being transported to Denver Health.
But Ostrem escaped in the red Mitsubishi he had been driving, and authorities looked for him all night before finding and arresting him around 8 a.m.
Ostrem had a history of run-ins with the police—most recently a driving while ability impaired conviction in Wheat Ridge in 2014. Neighbors said he was “weird” and kept to himself. Another neighbor told Denver7 Ostrem came off as rude and unapproachable.
“He was on the edge, not friendly, wouldn’t talk to anybody,” said neighbor Teresa Muniz. “You didn’t dare talk to him, because he always looked mad.”
Ostrem walked off his roofing job Wednesday morning in Frederick, the company confirmed, but was otherwise a “good worker,” fellow employees said. He also had several failed businesses, and declared bankruptcy in September 2015.
A law enforcement source also told Denver7 Thursday that Ostrem's mental health history was being investigated.
A national spokesperson for Walmart told Denver7 Friday morning the decision on when to reopen the store was being reviewed.