Besides being a Chicago police officer, Rivera was a beloved member of his neighborhood. His fellow officers carried his casket into the Church of the Annunciata ahead of his funeral as mourners crowded the streets nearby.
WATCH: Officer Rivera's casket carried into church
Officer Rivera's heartbroken mother, grappling with the loss, wore her son's pin. People with no connection to Rivera came out to show support. Long lines of students carrying balloons, flags and signs wrapped around the procession line to honor him.
"I see future officers standing there now," said Jane Addams Elementary School Assistant Principal Daniel Alvarez.
Many of the students from Jane Addams Elementary School are looking toward a future as a police officer.
"So our students understand the job the officers serve every day," Alvarez said.
Rivera, 23, had been on the force in the 6th District for two years was shot and killed in River North while sitting in a car with three friends.
RELATED: John Rivera, 23, identified as off-duty CPD officer killed in River North shooting
Menelik Jackson and Jovan Battle have been charged in the shooting. Police are still searching for a third man believed to be involved.
Investigators said Rivera may have been mistaken for someone in another group that had fought with the suspects hours earlier, or may simply have been targeted because he was Hispanic.
"It just disturbing, period," said Nora Vela, one of the many attendees of Rivera's funeral. "People are starting to hate people for just what they look like."
Hate crime charges could be filed, police said.
RELATED: 2 charged in fatal shooting of Officer John Rivera
Police said Rivera died in a final act of bravery: Shielding his girlfriend and other passengers from the gunfire.
Rivera's CPD colleagues say he was serious about policing but also had a wonderful sense of humor.
RELATED: Visitation held for CPD cop killed in off duty shooting
Rivera's partner released a heartfelt message, saying in part, "Even though your life was violently taken away too soon, I thank God for bringing us together. You were my right hand and someone I could always count on."
Sharing the beautiful & heartfelt tribute Officer Nate Smith (below) paid to his partner, his friend and his Brother Officer John Rivera (also pictured below with a hot dog bun in his pocket). This is how Officer Smith wants his Brother to be remembered 💙 pic.twitter.com/6va8uUVq8m— Chicago PD 14th Dist (@ChicagoCAPS14) March 29, 2019
Tom Gatton was Rivera's next door neighbor.
"He knew when he was 16 he told me he wanted to go on the job," Gatton said of Rivera's long held dream of being a Chicago police officer.
"He represents everything that we have in our community. I can only feel for his family and his mother," said Patricia Aguilera, another neighbor.