PORTLAND, Ore. (AP) — The 20-year-old who opened fire in a Bend, Oregon, supermarket, killing two before he turned the gun on himself, was a loner who was passionate about mixed martial arts and was known for getting into fights at the high school where he graduated in 2020.

The shooter, identified Monday by police as Ethan Blair Miller, of Bend, “tried to fight quite literally everybody” at Mountain View High School, former classmate Isaac Thomas told The Associated Press. Thomas said the gunman once threatened to shoot him after a fight at their school.

Police confirmed Monday they are investigating the “shooter’s writings” but declined to comment further on postings on several online platforms that appear to have been written by him in recent months.

In posts on several sites, someone who appears to be the gunman says he’s struggled to recover from the isolation and loneliness of the pandemic, expresses hatred for himself and indicates he planned to attack his alma mater next week, but couldn’t wait until then because “the Rage has become uncontrollable.”

Authorities sought a search warrant for digital devices found at the gunman’s apartment and it will take several days to go through those materials and develop a clearer picture, said Police Chief Mike Krantz.

“A lot of people sent us follow-up information about what has been posted on social media or other outlets and our investigators will sift through that information and make those connections — if it’s truly connected— and ensure that we have accurate information,” he said.

Police have no evidence of prior contact with the gunman and he had no criminal record in the area, authorities said.

Federal officials were also trying to determine where the gunman got the AR-15-style weapon and shotgun he brought into the store, whether the guns were obtained legally and why he chose the supermarket for his deadly rampage. They found three Molotov cocktails in his car along with a sawed-off shotgun and more ammunition in his apartment, said Bend police spokeswoman Sheila Miller, who is not related to the shooter.

Thomas, the former classmate, said the shooter had worked at the Safeway and Thomas had run into him there two years ago.

Police credited a Safeway employee and 20-year U.S. Army veteran who was killed in the shooting with possibly forestalling a worse outcome and called the actions of 66-year-old Donald Ray Surrett Jr. heroic.

“Mr. Surrett engaged with the shooter, attempted to disarm him and may very well have prevented further deaths. Mr. Surrett acted heroically turning this terrible event,” the police spokeswoman said.

About 150 people gathered in a Bend park on Monday night for a vigil to remember the victims. A church choir sang and a pastor and city officials spoke as people laid flowers.

“I’m so angry that lives were needlessly lost, that terror was experienced in our community,” Bend City Councilor Melanie Kebler told the crowd, according to Oregon Public Broadcasting.

Craig Van Bruggen attended the vigil and told the news outlet he was in the Safeway on the phone with his wife when the shooting began. He believes Surrett’s actions helped him escape without injury.

“Sounds like Donald potentially slowed down the shooter enough to save some lives, and he’s a hero,” Van Bruggen told OPB.

Customer Glenn Edward Bennett, 84, of Bend, was also killed Sunday evening, police said.

The gunman lived in an apartment complex behind The Forum Shopping Center. Witnesses said he began shooting Sunday evening as soon as he left the complex and continued firing as he entered the shopping complex’s parking lot and then went into the Safeway.

Bennett was killed at the store’s entrance, police said, and the shooter then moved through the aisles “spraying shots” from the assault rifle until Surrett confronted him.

Police entered the supermarket from the front and rear as shots were still being fired.

Debora Jean Surrett, the ex-wife of the Safeway employee killed in the attack, told AP in a phone interview that Surrett served in the Army for 20 years as a combat engineer. He wasn’t deployed to active combat zones, but during the 20 years they were married from 1975 to 1995, they were stationed in Germany three times and lived on military bases across the U.S.

The shooter graduated from Mountain View High School in Bend in 2020, according to online records, and Thomas remembered him as an extremely combative person who had few friends.

Thomas said he was suspended for a week as a freshman for fighting with the gunman. The gunman held onto a grudge from that fight and once threatened to shoot him, Thomas told AP.

“At one point he said he was going to shoot me and I was like, ‘Get over yourself’ because I didn’t think he had a gun, but I guess I was wrong,” Thomas said.

Thomas recalled running into the shooter in 2020 in the parking lot of the Safeway, where the gunman was gathering up carts as part of his job. He recognized him and threatened him again although several years had gone by, Thomas said.

Bend is a city of about 97,000 approximately 160 miles (257 kilometers) southeast of Portland, Oregon.

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Associated Press reporters Freida Frisaro in Fort Lauderdale, Florida and AP Researcher Jennifer Farrar in New York contributed to this report.

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