A Prince George’s County grand jury indicted a former FBI agent Thursday on a charge of vehicular manslaughter and eight other offenses stemming from a crash this year that killed a Brandywine teenager and seriously injured another teen.

Adrian N. Johnson was charged in the Feb. 7 crash that killed Lawrence Garner Jr., 18. Garner’s best friend, Robert Mitchell II, was injured.

Garner was headed south in his Hyundai Sonata in the 10600 block of North Keys Road in Brandywine when Johnson’s vehicle struck his car, police said. Johnson was driving a Mitsubishi Montero sport-utility vehicle, said Garner’s father, Lawrence Garner Sr., who went to the scene of the accident shortly after it happened.

Johnson, 37, had been driving north and veered across the center line, police said.

At the time, Johnson was an FBI agent assigned to the attorney general’s protection detail. He was off duty when the accident occurred.

Garner said Thursday that his son and Mitchell were heading home about 9 p.m. after playing basketball at a recreation center.

His son was working two jobs, at Home Depot and Edible Arrangements, and was planning to start classes in the spring at the College of Southern Maryland. He was going to study criminal justice, Garner said.

Garner, 43, said it was a jolt to learn that the driver of the SUV was an FBI agent. “That made me feel worse,” Garner said. “Being an FBI agent, you’re looked at as being a little more responsible.”

Mitchell, 19, suffered internal injuries but has improved, Garner said.

In addition to vehicular manslaughter, which carries a maximum penalty of 10 years in prison, the grand jury indicted Johnson on charges of reckless driving while under the influence and speeding.

“This is a case that will be fought at trial,” said Robert C. Bonsib, Johnson’s attorney. “We do not believe the evidence supports the charges of vehicular manslaughter.”

Staff researcher Magda Jean-Louis contributed to this report