EL CAJON, Calif. — The father of an unarmed black man who was fatally shot by police in a San Diego suburb on Saturday told hundreds of demonstrators who peacefully marched through downtown streets that his son’s death was a turning point in a struggle to change police practices.

Richard Olango Abuka called the El Cajon officer who fired his gun “a coward” and demanded that Police Chief Jeff Davis resign.

The orderly protest followed days of angry, sometimes unruly, protests that led to Friday’s release of two videos by the authorities, something that the family and community had urged.

The videos show the officer fired four times at close range almost immediately after Alfred Olango, 38, suddenly raised both hands to chest level and took what police described as a shooting stance. In addition to the videos, police showed the 4-inch electronic cigarette device Olango had in his hands when he was shot.

The shots came less than a minute after police arrived at the scene in response to Olango’s sister calling 911 and reporting he was acting erratically.

There was a modest police presence Saturday to direct traffic as demonstrators walked from one rally to another, shouting Olango’s name in unison as they made a short loop through the heart of the city of 104,000 people to Civic Center Plaza, which includes police headquarters. There were no reports of arrests or property damage.

“We must be united in this fight until we achieve our goals,” Richard Olango Abuka told the crowd. “Alfred’s death is going to be a turning point, and the change is now.”

The father didn’t directly address the videos but other speakers did. The Rev. Frank Placone-Willey of Summit Unitarian Universalist Fellowship in nearby Santee, California, read an email from a parishioner who watched them and questioned if police would have responded less aggressively if Olango were white.

“As long as Mr. Olango was not causing harm other than possibly blocking traffic, the officers should have taken steps to deescalate the situation,” Placone-Willey read from the email, sparking applause.

Several speakers said the incident highlighted a need for more police training on how to handle people who are in mental distress.

The incident is the latest in a series of fatal shootings of black men that have roiled communities across the U.S. It came weeks after fatal shootings by police in Tulsa, Oklahoma, and Charlotte, North Carolina.

Olango, a Ugandan refugee who arrived in the U.S. as a boy, had a criminal record that included drug and weapon charges but no violence. His family described him as a loving father and a joyful, happy person.

His mother said he suffered a mental breakdown recently after the death of his best friend. On Tuesday, his sister called 911 and reported he was acting strangely and walking into traffic by a strip mall.

The longer of the two videos released by police came from a surveillance camera in the drive-thru of a restaurant. It is roughly a minute, has no sound and police blurred out the heads of everyone in it.

Olango is seen walking through the parking lot and then stopping suddenly as Officer Richard Gonsalves approached, his weapon drawn at his side.

Olango, his right hand in his pants pocket, moved side to side and backed up toward a white pickup truck.

As Gonsalves moved in from the front, a second officer got out of a cruiser and approached from the side.

In the second video, taken on a cellphone by a witness in the drive-thru, Olango’s sister is seen approaching Gonsalves from behind and a woman can be heard screaming at Olango to put up his hands and telling police not to shoot.

Olango then bent over and assumed the shooting stance. Gonsalves quickly fired four shots at close range.

Associated Press writer Julie Watson contributed to this report.