SAN FRANCISCO (KPIX) — One year after a Vallejo police officer shot and killed Sean Monterrosa, his family marked the anniversary with a rally in San Francisco to demand justice and police reform across California.

Organizers held the rally in front of San Francisco City Hall Sunday afternoon. Monterrosa’s sisters — Ashley and Michelle — said young Black and Brown people continue to die at the hands of police officers and said reform can’t come soon enough.

“We’re trying to bring real change and accountability to the Bay Area but, more importantly, here in California. A lot of people think, with California being a progressive state — a blue state … (but) there’s a lot of injustices that happen day to day,” said older sister Michelle Monterrosa.

Civic Center Rally

Rally in San Francisco Civic Center plaza for Sean Monterrosa who was fatally shot by Vallejo police. (CBS)

She said the event aimed to focus on the life of the 22-year-old native San Franciscan but it was also a gathering to put pressure on elected leaders to speed up the pace of change.

“There’s power in unity. The more families we can get together to bring change to California, we’re going to do everything we can,” Michelle Monterrosa said.

Other families who lost loved ones in police shootings also joined the rally including the grandmother of Steven Taylor who was slain by a San Leandro officer; the family of Stephon Clark came from Sacramento.

“We bring all families together because, at the end of the day, the goal is to come together to dismantle the system that was never built for us,” Ashley Monterrosa said.

Sean Monterrosa was shot in a Vallejo Walgreens parking lot on June 2, 2020, when officers responded to reports of looting during a night of civil unrest in the wake of George Floyd’s death.

An officer, while sitting in the back seat of a police vehicle, fired a rifle through the windshield at Monterrosa. Vallejo police said the officer mistook a hammer carried by Monterrosa for a gun.

“Young people of color are unfairly penalized by the police system and we’re demanding accountability. If Sean was doing something wrong, we’ll find that out. All I know is he was on his knees with his hands up as a sign of surrender. He should’ve had the right to a court date,” said Beatriz Herrera, a professor at City College of San Francisco who taught Sean Monterrosa for a semester.

Last month, state attorney general Rob Bonta agreed to open a criminal investigation into the police killing.