The parents of a 29-year-old gunman, who attacked a Dallas immigration building in September, reported their son as “completely normal” before his move to Washington state. Upon returning home later, he believed he had radiation sickness, according to newly released police records.

Joshua Jahn began wearing cotton gloves to avoid plastic and practiced shooting with a newly purchased rifle in Oklahoma a month before the attack on a U.S. Immigration and Customs Enforcement facility, as detailed in a Fairview Police Department report.

Jahn killed two detainees and wounded another before taking his own life in the Sept. 24 shooting.

The Associated Press accessed these records through an open records request, which offered no insights into the motive behind the attack. Federal authorities previously mentioned Jahn inscribing “ANTI-ICE” on a bullet and his handwritten intentions to intimidate ICE agents.

On the day of the incident, Jahn’s parents informed the FBI that he occasionally talked about current events with his mother but was mostly silent. Described as a “loner” and deeply interested in artificial intelligence, his parents, Andrew and Sharon Jahn, did not return messages from AP on Monday.

The documents present Jahn as an unemployed man without social connections, spending his time playing computer games in his room in a Dallas suburb. According to his parents, he did not have any diagnosed mental or physical health issues.

The police and FBI haven’t commented immediately. Due to the government shutdown, the FBI stated its current focus is on national security, federal law violations, and crucial public safety operations.

Parents noticed changes after a move back to Texas

Jahn had been “completely normal” until he moved back from Washington state in the past five years, his parents said. He had previously taken classes at a Texas community college on and off for years, before driving across the country to answer an online advertisement for a seasonal job harvesting marijuana at a legal cannabis farm in Washington. Jahn appeared directionless and slept in his car for months, the farm’s owner Ryan Sanderson previously told the AP.

After returning from Washington because he could not retain a job, Jahn’s parents told the FBI he believed he was “allergic to plastic” and sought to avoid direct skin contact with the material. The county where he worked in Washington state was one of the sites for the secret Manhattan Project to develop atomic bombs. And they said their son became convinced that while in Washington, he had been “exposed to radiation from a nearby facility and was suffering from radiation sickness.”

Photographs from the scene of the shooting show a car affixed with a map depicting radioactive fallout in the U.S.

Records suggest his family life was far from harmonious. Jahn’s father had put pressure on his older brother to find a job or join the military after high school, and his mother called the police when the brother failed to show up to a meeting with an Army recruiter to sign enlistment papers in 2014, police records show.

Jahn’s mother called police on his sister one morning when she slept in rather than go to high school, moving out of the home for weeks as a teenager and once spray painting an expletive on the driveway of the family’s home.

But the Jahns financially supported Joshua, their youngest son, as he stayed in his second-floor bedroom and played computer games.

Practice shooting in Oklahoma

About a month before Jahn attacked the ICE facility, he went with his father to practice shooting at their property in Durant, Oklahoma, where they are building a new home. While Jahn’s father owned several guns, he was surprised to see his son pull an “old rifle” out of his car. Jahn told his father he had “recently” purchased the gun online, police records show.

According to the records, his mother told the FBI she had “no idea” her son owned a gun.

The FBI said previously that Jahn legally obtained the bolt-action rifle used in the shooting. But police records don’t say whether that was the gun Jahn used while target shooting.

Analysts with the Institute for Strategic Dialogue, which focuses on hate and extremism, working as part of a program organized by the Center for Internet Security, said it found that Jahn played games online under the username “Frank Hoenniker.” The username is apparently a misspelled reference to a cold and calculating character in author Kurt Vonnegut’s 1963 satirical novel, “Cat’s Cradle,” about politics, religion and nuclear proliferation.

Steam, a game distribution platform, shows Jahn logged more than 11,000 hours on first-person shooter and survival games.

Brook is a corps member for The Associated Press/Report for America Statehouse News Initiative. Report for America is a nonprofit national service program that places journalists in local newsrooms to report on undercovered issues.