The man authorities say gunned down two people inside a Texas church Sunday had a lengthy criminal history, including a weapons arrest in New Jersey.

Keith Thomas Kinnunen, 43, was shot and killed by volunteer security at the church in Tarrant County after shooting and killing two other men, according to law enforcement in Texas. The FBI is taking part in the investigation into Sunday's church, and a motive remains unclear.

As reported at the time by MyCentralJersey.com, Kinnunen was arrested in September 2016 by police in Linden, who said they found Kinnunen in possession of a 12-gauge shotgun and rounds of ammunition wrapped in plastic, riding a bicycle near the Phillips 66 refinery.

Kinnunen told Linden police he was homeless and traveled often, taking "photos of interesting sites" according to the same report. Kinnunen was charged with unlawful possession of a weapon.

Jack Wilson, the security volunteer who shot and killed Kinnunen, has said Kinnunen used a short-barreled 12-gauge shotgun with a pistol grip at the church, the Associated Press reports. Shotguns with barrels less than 18 inches long are only legal in Texas if  registered with the Bureau of Alcohol, Tobacco, Firearms and Explosives.

Kinnunen's criminal history also included arrests in Arizona and Oklahoma, for assault and disorderly conduct and assault and battery, respectively, The New York Times reported.

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