Sgt. Joe Grubbs said the preliminary investigation revealed the driver of a 1998 Ford Expedition turned onto 30th Street from Q Street, and the boy was struck when he ran in front of the vehicle.
The coroner's office identified the boy as 4-year-old Gregorio Edward Leyva.
Thursday, Leyva's mother Anna Maria Palomino spoke to Eyewitness News.
She said Gregorio was a kid who loved to play ball, sing and dance.
"He was a funny kid, loved to talk to other people," Palomino said. "I miss my son very much."
Paramedics were performing CPR on Gregorio before he was taken to Memorial Hospital, where he was pronounced dead.