Terrence Sterling, the Fort Washington motorcyclist who was killed by a D.C. police officer in September, was shot once in the neck and a second time in the back, according to a lawsuit filed by his family.

The $50 million civil lawsuit was filed Thursday against the District and its police department.

Sterling, 31, was shot during the early morning of Sept. 11 after police spotted a motorcyclist driving erratically, officials said. Police said that the officer, Brian Trainer, opened fire when Sterling’s motorcycle struck the door of a police cruiser as the officer was getting out.

In the lawsuit, Sterling family’s alleges that Trainer “shot and killed Mr. Sterling from the safety of a police vehicle despite the fact that Mr. Sterling was unarmed and posed no danger” to Trainer or anyone else.

[One month after D.C. police shooting, answers remain elusive]

Terrence Sterling

The lawsuit was filed in D.C. Superior Court. Sterling’s family is represented by Baltimore attorneys Jason Downs and William “Billy” Murphy Jr., who represented the family of Baltimore’s Freddie Gray. Gray, 25, died last year the after being injured in police custody. The city of Baltimore later settled with the Gray family for $6.4 million. As part of that settlement, officials began equipping city officers with body-worn cameras.

In September, the D.C. Medical Examiner’s Office said Sterling had bullet wounds to his neck and back. But at the time, it declined to reveal publicly if the wounds were caused by one bullet or two.

According to the lawsuit, the medical examiner’s report showed Sterling was shot twice.

A D.C. police spokesman said the department would not comment on pending litigation.

Policing experts said additional evidence would have to be considered to determine the positions Trainer and Sterling were in when the shots were fired. Geoffrey Alpert, a criminologist with the University of South Carolina, said Sterling may have been facing away from the officer, or his body may have quickly turned.

(Claritza Jimenez,Jenny Starrs/The Washington Post)

“I’ve seen it happen frequently when people are running away. If the motorcyclist is driving toward me and shot in the back, he would have to turn, twist and move in order for the bullet to go in his back,” Alpert said. “But I’m not sure how that would work when he’s riding a motorcycle.”

[Motorcyclist killed by police had gunshot wounds to his neck and back]

Meanwhile, prosecutors from the District’s U.S. Attorney’s Office, which handles excessive force allegations involving D.C. officers, have been reviewing the Sterling case to determine if any criminal charges should be filed. According to two people familiar with the investigation, at least three witnesses have been before a grand jury over the past months.

Howard Dorsey Jr., one of the witnesses to the shooting, said he testified before the grand jury for about 15 or 20 minutes last month, describing what he saw the night Sterling was killed.

In a previous interview with The Washington Post, Dorsey questioned whether the police had given Sterling appropriate warning before shooting.

“The cops said no words, nothing,” he said at the time. “No ‘freeze.’ ”

Dorsey more recently said his memory of the shooting hadn’t changed.

“Everything is still the same,” he said.

Police have said the encounter between officers and Sterling began about 4:20 a.m. when officers got a call about a motorcycle driving recklessly in the Adams Morgan area. Officers later saw the motorcycle near Third and M streets in Northwest Washington.

Two witnesses have told The Post that a marked police cruiser pulled into the roadway ahead of the motorcycle.

Trainer began to exit the passenger’s side of the cruiser to stop Sterling, police have said. At that point, according to police, Sterling drove the motorcycle into the car door and the officer fired his weapon.

City officials later said Trainer failed to turn on his body-worn camera until one to three minutes after the shooting. They said the camera should have been activated at the beginning of the pursuit or at the initial interaction.

The lawsuit claims D.C. police “failed to properly train its officers to use” the body cameras, which the Sterling family attorneys argue “failed to ensure public safety.”

The lawsuit also alleges that D.C. police had “actual or constructive knowledge that its police officers routinely failed to properly use” the cameras. The lawsuit cites two internal memos by D.C. police, one dating back to 2015 and the other dated April 1, 2016, in which police officials acknowledged at least 15 incidents in which its officers failed to activate their cameras during on-duty interactions.

Sterling’s attorneys also made an unusual request of asking a judge to require any D.C. officer equipped with a body camera to activate the camera when they report for duty, or otherwise be in violation of a court order.

Four days after the shooting, D.C. police senior officials implemented department-wide procedures requiring its officers to acknowledge over the radio that they have turned on their cameras when responding to a call.

The lawsuit also names Trainer and his partner, who has not been publicly identified, as defendants.

Justin Wm. Moyer and Peter Hermann contributed to this report.