A Jackson, Mississippi, police officer accused of sexually assaulting a 15-year-old girl over the last six months shot and killed himself on Monday amid an investigation into the claims.

James Hollins, 29, was to undergo an internal and external investigation, Sergeant Roderick Holmes, who works for the Jackson Police Department, said in a press conference. Hollins had been placed on leave on Sunday after the teen's family alleged that there were videos of the two being intimate in his squad car.

On Monday, prior to Hollins' death, Holmes held a press conference address the allegations. Holmes said, "All matters involving assault we take very seriously, We want the family to understand that if at any point in time, there's evidence of wrongdoing going on, we will not hesitate to take action."

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Attorney Lisa Ross represents the mother of the 15-year-old and told Jackson's WLBT-TV that the mother reported the alleged misconduct to Chief James Davis on Saturday. He was given approval by the mayor, Chokwe Lumumba, to place him on leave.

On Monday afternoon, Hollins reportedly shot himself with a gun while on Inerstate I-220. He was in a Dodge Charger, reports police spokesman Roderick Holmes, and was found at approximately 12:45 p.m. after pulling off the side of the highway, USA Today reports. He used the gun of another officer. Following his death, both lanes of the interstate were closed for over two hours as police conducted an investigation.

"It’s not known to us now if the officer even knew their weapon had been taken in the moment," said Mayor Lumumba.

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Pictured is a police cordon that surrounds the scene of a house fire in Sycamore Lane, Stafford, on Feb. 6, 2019 in England. Christopher Furlong/Getty Images