People there are demanding accountability for police use of force. The issue is bigger than Lopez now, but it begins with him.
This wasn't the first march for Lopez in Santa Rosa, just the latest and probably not the last.
"This is a continuation of the civil rights movement?" said one demonstrator.
The rally was a symbol of the outrage that began last fall when Sonoma County Sheriff's Deputy Erick Gelhaus shot and killed the 13-year-old after mistaking an AK-47 look-a-like pellet gun for the real thing. Months later, a memorial still stands in the spot where Lopez fell. Neighbors still tend to it.
Neighbor Aubrey Martin says they maintain the memorial "because a little boy was murdered here. It matters a lot."
The Latino community calls it murder. Gelhaus called the shooting self-defense. The lingering question is what will Sonoma County District Attorney Jill Ravitch do with the case?
We asked rally organizer Phil Cairo if he thought Gelhaus would be charged and he replied, "In all honesty, no. And that is essentially why we are here."
That's the rub in this community. Ravitch is up for re-election in June. Some of her strongest political and financial support comes from law enforcement. These protestors want Ravitch to turn this case over to California Attorney General Kamala Harris.
"Jill Ravitch is more concerned and worried about endorsements, primarily the endorsements coming from the police department, the Sonoma County Sheriff's Department and correctional officers union than she is really invested in what the people would like," said Cairo.
This group of people, anyway. But not everyone.
"I think they're just a bunch of vigilantes. They weren't there. I wasn't there and I believe that no sheriff or policeman wants to try to kill somebody," said resident.
The district attorney's office did not return phone calls on Monday.