Federal prosecutors said this weekend they have filed murder charges against a D.C. government employee who hit a Metropolitan Police Officer with his car and mortally wounded him days before Christmas.

The U.S. Attorney’s Office for the District of Columbia said Jerrold Lonnell Coates, 47, was charged with second-degree murder while armed in the Dec. 23 crash on Interstate 695 that left Officer Terry Bennett fighting for his life. Officer Bennett died of his injuries on Jan. 6.

Police said they arrested Mr. Coates, who works for the city’s Department of Parks and Recreation, on Friday. He made his initial court appearance on Saturday.

“These cases are extremely difficult, and they’re even more difficult when the victim is a fellow officer,” Metropolitan Police Interim Chief Jeffrey Carroll said. “I ask that you continue to keep Officer Bennett’s loved ones, and the members of our department in your thoughts and prayers in the days ahead.”

Investigators said Officer Bennett had responded to a minor crash around 9:50 p.m. on Dec. 23 on I-695 after a driver had run out of gas and another driver rear-ended them.

While Officer Bennett waited for a tow truck to arrive, a man driving a Volvo XC90 sped in between the slowed traffic and hit the officer, investigators said. Officers rushed the wounded Officer Bennett to a hospital.

Authorities said medics tended to the Volvo driver, who had been knocked unconscious by the collision, by administering Narcan to him.

The stranded motorist who had run out of gas was not injured in the crash.

Officials said Officer Bennett, 32, had been in grave condition after the incident. He was an eight-year veteran of Metropolitan Police and worked in the department’s 1st District.

“Officer Terry Bennett tragically lost his life in the line of duty while doing what he was known to do — helping and caring for the people around him,” D.C. Mayor Muriel Bowser said in a statement. “He was a father, a husband and a beloved member of our community.”

The Metropolitan Police Department on Thursday held a procession for the fallen officer.

Before joining the MPD, Officer Bennett worked as an associate dean at his alma mater, Ballou Senior High School in Southeast. He later served as assistant head coach and defensive coordinator for the Knights football team.

“Through his coaching, mentorship and public service, he impacted the lives of countless students and Washingtonians and leaves behind a legacy of love and courage,” Ms. Bowser said.