SAN DIEGO -- A 19-year-old man accused of killing a University of California, San Diego doctoral student in a hit-and-run crash in La Mirada in Los Angeles County was charged Friday with vehicular manslaughter with gross negligence and hit-and-run causing death.

Authorities said Erik Aguirre, of La Mirada, was behind the wheel of a Chevrolet Astro minivan that struck 28-year-old Liberty Jaswal in the parking lot of a Del Taco restaurant, dragging him 60 to 70 feet.

Jake Wilson, a friend of Jaswal and a witness to the accident, said the UCSD student was struck around 2:15 a.m. Saturday.

Jaswal was declared dead about two hours later at the University of California, Irvine Medical Center.

Two passengers who were in the van, an 18-year-old woman and a 17-year-old boy from Whittier, contacted authorities on their own and were cooperating in the investigation, according to Lt. Robert Esson of the Los Angeles County Sheriff's Department.

Jaswal and five friends had just come from a billiards hall on the other side of the parking lot when he was run over by the van, which was going 15-20 mph, deputies said.

After the accident, a female passenger in the Astro van was overheard yelling "go, go, go" as the male driver accelerated away, authorities said earlier.

Aguirre was arrested in the predawn hours Wednesday, the same day friends and family of Jaswal had planned to offer a $25,000 reward for information leading to an arrest and successful prosecution in the case.

Jaswal, a resident of Phillips Ranch near Pomona, was pursuing a doctorate in philosophy, after graduating from the University of California, Berkeley.

Wilson described his friend as a peaceful person who loved animals, nature and the wilderness and "never raised his voice to anybody, ever."

Aguirre, who was being held on $1 million bail, appeared Friday in Downey Superior Court, but his arraignment was postponed until July 10.