The social media profiles for the alleged killer in a Burlington, Washington shooting spree depict a young man fascinated by guns, video games, and serial killers.

Police arrested 20-year-old Arcan Cetin on Saturday night, after he allegedly opened fire in a Macy’s cosmetics department in a mall north of Seattle, killing four women and one man. Investigators have not announced a motive and say they have no evidence to suggest the shooting was an act of terrorism. But Cetin’s social media and court records suggest a long-held interest in guns, one which grew increasingly troubled within the last year.

Security footage from the Cascade Mall in Burlington, Washington appears to show Cetin entering the mall twice on Friday night: once unarmed, then approximately 10 minutes later, when he returned with a rifle. Witnesses told local media that they heard the gunfire approximately 12 times. Four women died on the scene, while the male victim died later in the hospital.

Cetin had access to guns since childhood, his social media profiles indicate. In a series of undated MySpace photographs uploaded before March 2014, he shows off a series of guns. In one picture, a young Cetin holds his uncle’s M16, a rifle similar in make to the AR-15, a weapon with a dark reputation as a favorite for mass-shooters. Two other pictures, which appear to have been taken at a later date show him holding another rifle and a handgun.

Cetin, who posted frequently about video games and sometimes live-streamed Call of Duty Games, was also apparently interested in a career in the armed forces. He tweeted about his friends in the Reserve Officers Training Corps, and a high school classmate confirmed to The New York Times that Cetin had been active in the military training program.

References to guns and Cetin’s apparent fixation with Russia also made their way into his Tumblr, where he posted under the username “arcanmotherrussiavodkaandak47”.

“Truth is: You are a very odd character,” a former classmate wrote in 2012 on Cetin’s now-deleted Facebook profile. “You were always going on about being Russian and stuff like that, but under that you really supported America (or so it seemed to me) and I always thought that was really cool. Maybe we will have ROTC together again next year! :D even if we don’t, try to keep up with the Mother Russia thing!”

But Cetin—who as a child immigrated to the United States from Turkey, not Russia—had an increasingly troubled record, one that showed on his social media profiles as well as court documents.

On Tumblr, Cetin liked and reblogged multiple posts about serial killers, including a picture of a four-year-old Ted Bundy smiling on a sled, and a list of murders who collected souvenirs from their killings.

Court records obtained by the Seattle Times reveal a drunk driving arrest, and charges of three domestic violence assault against his stepfather. During a December 29 court appearance for his domestic violence charge, a judge ordered that Cetin would not be allowed to possess firearms. Cetin’s stepfather argued in Cetin’s favor, asking the judge to forgo a no-contact order, adding that Cetin was “going through a hard time.”

While the alleged shooter’s motives remain unknown, law enforcement officials told Washington’s KING 5 television station that the Cetin’s ex-girlfriend had worked at the Macy’s until recently, adding that Cetin appeared to have stolen the guns from his father.

On Facebook, a number of Cetin’s female classmates accused him of sexism.

“I fucking went to high school with this perverted piece of shit,” wrote Uhlaine Finnigan, a former classmate who said she nearly went to the mall the night of the shooting. “His name is Arcan Certin, a fucking degenerate. He'd grab and slap my friends and I's asses and even caressed my friends chest, along with other women. Has been known to be violent towards girls too. This was a target against women. Rot in hell.”

Multiple women, allegedly former classmates, echoed Finnigan in the comments.

“Holy shit dude I met him in 4th grade,” one wrote. “And even then he was sexually harassing my friends and I. What the fuck.”