Ahmad Al Aliwi Alissa, 21, “was kind of scary to be around,” Dayton Marvel, who was on a wrestling team with the suspect, told the Denver Post.
Alissa once threatened to kill people during an especially heated moment, Marvel said.
Angel Hernandez, another former wrestling teammate, recalled how another wrestler at one point teased Alissa, telling him that if he was a better wrestler, he would have won a match that he lost.
Alissa “just lost it” and “started punching him,” Hernandez said.
Both said Alissa often talked about the idea that he was targeted by others because of his Muslim faith.
“He would talk about him being Muslim and how if anybody tried anything, he would file a hate crime and say they were making it up,” Marvel said. “It was a crazy deal. I just know he was a pretty cool kid until something made him mad, and then whatever made him mad, he went over the edge—way too far.”
According to a Facebook page appearing to belong to Alissa, he was born in Syria in 1999 and wrestled while attending Arvada West High School. In posts on the page, the man referred to racism and Islamophobia.
In one post, Alissa said he was being stalked by someone because of racism.
Alissa’s brother, in an interview with the Daily Beast, described him as “anti-social” and paranoid. The brother, who did not return a voicemail, said his sibling didn’t commit the shooting due to political or ideological reasons, blaming what happened on mental illness.
Boulder County District Attorney Michael Doherty told reporters on Tuesday that officials do not know what motivated the mass shooting.
“Why did this happen? We don’t have the answer to that yet,” he said.
“It’s been less than 24 hours since the shooting took place. And it’d be premature for us to draw any conclusions at this point in time,” added Michael Schneider, the FBI special agent in charge in Colorado.
Officials declined to detail any of the statements that the suspect has made so far to investigators.
“We’ll be providing those in the weeks ahead,” Doherty said. “I know that there’s an extensive investigation just getting underway into his background. He’s lived most of his life in the United States, and beyond that we’re still in the very early stages of the investigation.”
According to an arrest affidavit (pdf), Alissa surrendered to SWAT officers after carrying out the shootings. The suspect, who had removed his clothing and was dressed only in shorts, had blood on his right thigh.
Two officers walked the man to the corner of King Soopers, where the shootings happened, and asked if there were any other suspects.
“The suspect did not answer questions, though he asked to speak to his mother,” the court filing said, adding that he later told paramedics he was not taking any medications and confirmed his name and birth date. No other questions were asked.