A UK immigrant and career criminal charged with a “pure evil” killing spree in Georgia that claimed the life of a Department of Homeland Security employee and two others was found dead in jail Tuesday night, according to authorities. 

Olaolukitan Adon-Abel, 26, was discovered dead in his cell. Authorities performed lifesaving measures on the convicted felon, but he was ultimately pronounced dead, according to the DeKalb County Sheriff’s Office. 

His cause of death is not yet known, but officials do not suspect foul play and will conduct an internal review, cops said. 

Adon-Abel, a convicted felon immigrant who was naturalized under the Biden administration while serving in the US Navy, allegedly shot and stabbed DHS auditor Lauren Bullis, 40, as she took her dog Sancho out for a walk around 7 a.m. April 13.

DHS Secretary Markwayne Mullin called the crime “pure evil” that “devastated our department.”

The deadly spree started hours earlier outside a Checkers restaurant on Wesley Chapel Road in DeKalb County, when the suspect gunned down Prianna Weathers, 31, around 1 a.m., cops said.

The madman then drove roughly 16 miles before he allegedly opened fire on Tony Mathews, 49, who was homeless and sleeping outside the Kroger grocery store in Brookhaven at about 2 a.m.

Several hours later, Adon-Abel allegedly shot and stabbed Bullis roughly 15 miles away, according to authorities.

Bullis’ husband, Jimmie, reunited with their beloved dog, who ran off after the tragic attack, he previously told The Post.

Adon-Abel’s roommates told the Associated Press that he got into an intense argument over the air conditioning in their home and stormed out before going on the killing spree. 

The accused killer, who became a naturalized citizen in 2022 while he served in the Navy and was stationed in the San Diego area, had a lengthy rap sheet before the heinous murders, according to Mullin.

“He possesses a prior criminal record that includes convictions for sexual battery, battery against a police officer, obstruction, and assault with a deadly weapon, vandalism, and now stands accused of murdering [DHS] employee Lauren Bullis by shooting and stabbing her while she walked her dog,” he said in a statement. 

“These acts of pure evil have devastated our department, and my prayers are with the families of the victims.”

It wasn’t immediately clear if Adon-Abel’s prior convictions predated his arrival in the US.

Investigators haven’t revealed a motive in the deadly spree, but the victims appeared to have been targeted at random.

With Post wires