PITTSBURGH — A white Pennsylvania police officer who shot and killed an unarmed black teenager last year goes on trial starting Tuesday in a case that could put him behind bars for life.

Lawyers for Michael Rosfeld, 30, are expected to argue that the June shooting of Antwon Rose II after a traffic stop in East Pittsburgh was justified, while prosecutors push for a conviction in the criminal homicide case.

The shooting was captured on video by bystanders and posted online, triggering a series of protests in the Pittsburgh area last year that included a late-night march that shut down a major highway.

A jury of six men and six women, including three African-Americans, was selected in Harrisburg last week and will be sequestered in a Pittsburgh hotel for the duration of the trial, expected to take a week or more.

Antwon Rose was shot by police after running from a car suspected in a shooting in Pittsburgh. via Facebook

Rose, a 17-year-old high school student, had been the front-seat rider in an unlicensed taxicab when the back-seat passenger rolled down a window and shot at two men on the streets of North Braddock.

The shooter was Zaijuan Hester, 18, of Swissvale, who pleaded guilty Friday to aggravated assault and firearms violations for the incident that wounded a man in the abdomen. Hester told a judge he — and not Rose — did the shooting. A judge ruled Monday jurors will hear evidence of that incident, but likely will not hear about a robbery that occurred several hours earlier.

The drive-by shooting in North Braddock led Rosfeld, of Verona, to pull over the unlicensed cab a short time later. While Rose ran from the vehicle, Rosfeld shot him three times, in the right side of his face, in his elbow and in his back, going through his heart and lung.

Authorities have said Rose had an empty ammunition clip in his pants when he was killed but not a weapon. Two handguns were recovered from inside the vehicle.

The police affidavit used to charge Rosfeld said he gave conflicting statements to investigators, including that he saw something in Rose’s hand that Rosfeld thought was a gun.

“This observation caused him to step from behind the cover of his car door to acquire a better view,” police wrote in the affidavit. “He then fired his weapon.”

Investigators have said Rosfeld subsequently told the detectives he did not see a gun when the passenger ran.

“When confronted with this inconsistency, Rosfeld stated he saw something in the passenger’s hand but was not sure what it was,” police wrote. “In addition, Officer Rosfeld stated that he was not certain if the individual who had his arm pointed at him was still pointing at him when he fired the shots.”

Trey Willis, 32, of Washington, Pennsylvania marches during a protest a day after the funeral for Antwon Rose II on June 26, 2018 in downtown Pittsburgh. Justin Merriman / Getty Images file

During jury selection, defense attorneys repeatedly said jurors would be asked to determine if the shooting was justified.

“He’s very, very remorseful. He’s not remorseful because he’s been charged. He legitimately is sad that this happened,” defense attorney Patrick Thomassey told the Pittsburgh Post-Gazette last year. “Mike kept saying, ‘I can’t believe this happened. I can’t believe that kid didn’t have a gun in his hand.’”

Rosfeld had been on the East Pittsburgh Police for just a few weeks after working for other departments over seven years.

After the shooting, East Pittsburgh shut down its police force and began to rely on state police to cover the territory.