The fatal shooting of a man in a parked car by Phoenix police officers over the weekend, captured on video in gruesome detail, is fueling a new round of protests against violent policing tactics.

The video showed several uniformed officers surrounding a parked car while pointing their guns at the man inside the vehicle. One of the officers shouted at the man, threatening to shoot him. The Phoenix Police Department identified the man as James Porter Garcia, 28.

Then, in front of witnesses who were recording the episode, the officers unleashed a volley of gunfire. The victim was taken to a hospital where he was pronounced dead, according to a statement by the Phoenix Police Department.

The shooting in the city’s Maryvale neighborhood comes at a time when cities around the United States are grappling with anger over the deaths of African-Americans and Latinos at the hands of the police. Elsewhere in Arizona, the police in Tucson came under scrutiny in June over the killing, also captured on video, of Carlos Ingram Lopez.

“It does not shock us that despite all the scrutiny from community Phoenix PD continues to respond violently to calls,” Carlos Garcia, a member of the Phoenix City Council, said in a Facebook post about the episode. He added, “We cannot allow for dishonest narratives to be built by violent departments.”

Protests over the killing broke out in Phoenix on Sunday night, with dozens of demonstrators marching to the Maryvale Estrella Mountain police station. About 30 officers in riot gear blocked access to the building during the protest, according to reports on social media.

Details surrounding the fatal shooting remain murky. The Police Department in its statement said officers were responding to a 911 call about an aggravated assault.

The department said James Garcia had a handgun and pointed it at an officer before being fatally shot by the police. Sgt. Mercedes Fortune, a spokeswoman for the department, said officers talked to Mr. Garcia for about 10 minutes before shooting him. Ms. Fortune said he told officers to shoot him and lifted his gun toward the officers before he was killed.

The department released body-camera footage from an officer who arrived on the scene after the shooting, showing a handgun being retrieved from inside the vehicle.

Still, Steven Merry, a friend of the victim, told local media that the man was unarmed.

“They put the gun on his head like this and they’re still telling him not to move, to get his hand off a gun he don’t have and then they shot him again,” Mr. Merry told KSAZ.

Activists are demanding the release of body-camera footage from the two officers who fatally shot Mr. Garcia, though it remains unclear when such video could be made available. Ms. Fortune contended on Monday that releasing the additional footage would compromise the investigation of the killing. Police departments in Arizona often take weeks or months to respond to such requests.