"There were some witnesses obviously around, we have some video of it, and they're just standing there. Nobody's come forward, they didn't speak to the police, and that's the troubling thing," said LAPD Det. Felix Padilla.
A camera mounted on a hotel recorded the scene as a pickup truck parked in the 500 block of Stanford Street pulled away from the curb.
Police said the victim, 58-year-old Roosevelt Turner, had been standing at the driver's side door. They said he was running alongside the truck when he fell and was run over.
The surveillance video is all police have to work with.
"You just don't leave a human being lying on the street to die," Padilla said. "The humane thing is to speak to the police."
Anyone with information is urged to call the LAPD Central traffic division at (213) 972-1853.