He says children are the key to stopping violence, but they need good role models.
"This is an effort for us to show how you live peace. This is hopefully a great statement for our community. We have so much support," said Carroll.
City and community leaders marched down Martin Luther King Jr. Boulevard as a show of strength.
They were joined by law enforcement officers, who say it's important to realize the city can't arrest its way out of gang problems.
They say keeping children out of gangs in the first place is a far better solution than trying to rehabilitate them after the fact.
San Francisco Mayor Gavin Newsom also joined the march, saying this kind of violence isn't unique to Southern California.
