A motorcade signaled the boy's arrival. He's 5-year-old Greggorio Casillas, and he was visibly excited to start the first day of kindergarten being greeted by waiting officers.
Pomona police Chief Michael Olivieri was on hand to welcome Greggorio and his mother.
"We're hoping that he remembers this day forever. We hope that when he gets older that he understands just how important the sacrifice his father made is to all of us," Olivieri said.
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Last March, 30-year-old Gregory Casillas was shot and killed in the line of duty. Casillas had been with the police department for only six months.
On Wednesday, Olivieri walked Greggorio to class with officers and onlookers cheering him on.
"At first we didn't know what it was, so then we did figure out what it was, we saw the little boy walking. We thought it was really neat. He seemed really excited and happy to see that support for him," parent Johnny Hensley said.
More than 70 officers with the Pomona, Upland and Ontario departments as well as the California Highway Patrol came out to support Greggorio.
Olivieri said he hopes to be there to congratulate him when he graduated high school.
"I don't think our bond with that family will ever end," he said.