Flores was stabbed to death while walking home from school in 2016.
Tuesday, residents hugged and cried after learning about an indictment in the boy's murder.
"There should have been no reason for him to have taken the life of this sweet little boy," said Stella Mireles-Walters. "No reason at all. Justice will be served."
Mireles-Walters founded "Safe Walk Home Northside" after Flores' death. Volunteers with the organization keep an eye on the neighborhood kids as they walk home from school.
"We never gave up. Sometimes when we become and people were starting to forget we said 'Don't forget! Don't forget. This case will be solved. One day we're going to find who killed him,'" said Mireles-Walters. "And here's the day."
Speaking on behalf of the Flores family, spokesperson Jose Vega told ABC13 Eyewitness News that Flores' family is relieved, but they're still waiting for a guilty verdict.
"We're not going to stop until justice is served. We can't celebrate yet. That's just the point that we're making," Vega said.
He is planning a concert on August 18 to create a scholarship in the 11-year-old's name.
On Tuesday, the memorial to Flores continued to grow as residents placed flowers and balloons at the site where he was murdered.
"You will never, ever be forgotten," said Mireles-Walters. "Never."
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