One message rang clear through the cries of protesters this week after a police officer shot a black teenager: Allegheny County District Attorney Stephen Zappala needs to go.

“This is a referendum on Stephen Zappala,” shouted Jasiri X, an activist and musician at a Thursday night protest. “He has always stood with brutalizing police officers and he’s never stood with the oppressed black and brown people of Allegheny County.”

Zappala will ultimately decide whether to prosecute East Pittsburgh police officer Michael Rosfeld, who killed 17-year-old Antwon Rose at a traffic stop Tuesday night.

Rose was one of two passengers in the vehicle, which police suspected of having been involved in an earlier shooting. Rose was shot while fleeing the vehicle. He was unarmed, though two guns were found in the vehicle.

“We would like to see Zappala charge this officer with the crime that he committed -- murder,” said Brandi Fisher, President of the Alliance for Police Accountability.

Fisher said she'd rather have Pennsylvania Attorney General Josh Shapiro handle the case. She said Shapiro would have a level of independence that Zappala lacks.

Other activists, meanwhile, want to change state law so that the Attorney General investigates any deaths that involve police.

In a statement, Shapiro said, he couldn’t take up the case unless the District Attorney asked him to do so.

“The loss of any young life is deeply painful,” Shapiro said. “I expect local law enforcement to give this the thorough investigation it deserves."

Zappala has served as Allegheny County’s District Attorney since being appointed in 1998.

In 2016, he ran for Pennsylvania Attorney General against Shapiro, a fellow Democrat. Zappala's campaign aired an ad touting his willingness to convict officers for misconduct.

The ad referenced Pittsburgh Housing Authority police officer John Charmo, who shot black motorist Jerry Jackson in the Armstrong Tunnel in 1995. The shooting took place before Zappala became District Attorney, but Zappala prosecuted the case years later. After a mistrial, Charmo pleaded guilty to involuntary manslaughter.

A spokesman for Zappala’s office did not return a request for comment Friday. His office previously said it would not speak on the Antwon Rose case until next week. But it's rare for a prosecutor to win a conviction or guilty plea against an officer.

Marty Marks, who worked on Zappala’s 2016 campaign and considers him a friend, said Zappala “believes in justice and fairness, and [there’s] no doubt in my mind that that’s what he’ll seek here in this situation.”

Marks noted that during that 2016 campaign, the Fraternal Order of Police endorsed not Zappala but Shapiro. That’s proof of Zappala’s independence, he said.

Rich Long, the Executive Director of the PA District Attorneys Association, said that Zappala had a reputation as “a very proactive District Attorney who has the respect of his peers.”

None of that impresses activist Brandi Fisher.

“Are we comparing this to how many cases where he didn’t charge the officer? Because if we’re looking at that, I think he has a very bad record,” she said.

For example, Zappala has previously drawn fire for not charging three Pittsburgh police officers involved in a 2010 altercation with Homewood teenager Jordan Miles. The case prompted accusations of racial profiling, though federal investigators also declined to press charges.

Fisher pointed out that Zappala is up for election in 2019.

“People are tired of waiting on a system that never serves them justice," she said.