A car-to-car shooting near Dorsey High School left two people dead -- one of them a pedestrian who was struck by the victim's vehicle -- and authorities are asking for the public's help as they search for the shooter.

Police responded about 8:30 p.m. Monday to the 4800 block of West Rodeo Place, not far from the intersection of Rodeo Road and Crenshaw Boulevard, and discovered the driver had been shot, according to Officer Mike Lopez of the Los Angeles Police Department's Media Relations Section. The man -- identified by the coroner's office as Harrison Kristol, 20, of Los Angeles -- died at the scene.

The victim's vehicle then struck and killed a pedestrian on a skateboard, the LAPD said. The man died at the scene, the coroner's office reported. He was later identified as 22-year-old Royce McFarland.

As the suspect's vehicle was speeding away, it struck and critically injured a bicyclist at Farmdale Avenue and Exposition Boulevard, Herrera said.

"This was like so many of the killings we've had here in South Los Angeles--senseless, without any reason at all," said Cpt. Peter Whittingham of the LAPD's South Bureau Homicide Division.

Witness Bridgette May said she heard three shots, then stopped to help a woman get out of the victim's vehicle.

"They was just coming from the grocery store, getting ready to go home and cook some crab, and she said somebody drove by and started shooting at them," May said.

Firefighters sent to the scene discovered one person was trapped beneath a vehicle, and another person had been shot nearby, according to Brian Humphrey of the Los Angeles Fire Department.

Metro's Expo Line service was disrupted at the Farmdale station as police conducted their investigation at Exposition Boulevard and Farmdale Avenue. Passengers were transported around the station using Metro buses. Normal service resumed about 11 p.m. Monday.

No information was immediately available about the shooting suspect, who had left the scene by the time police arrived, and it was not immediately clear if the shooting was gang-related, Lopez said.

Authorities described the suspect's vehicle only as a light-colored sedan. They do not have any further descirption of the car or the suspect, and have not uncovered any surveillance video that may help them. Officials plan to offer a reward for anyone who comes forward with information on the case at a Thursday news conference.