SAN PABLO -- A Richmond man was fatally shot in San Pablo on Thursday afternoon, police said, marking the city's first homicide since 2012.

Richmond resident Franklin Lopez-Guardado, 19, died following a shooting on 2100 block of Dover Avenue just before 4:30 p.m., according to information from a police sergeant and the Contra Costa County Coroner's Office.

Lopez-Guardado was taken by medical helicopter to John Muir Medical Center to be treated for his injuries but died at the hospital, officials said.

No arrests have been made and no motive has been established for the shooting, but witnesses saw three men fleeing the scene and one of them had a handgun, police said.

The killing marked San Pablo's first homicide since 2012, when seven people were killed in the city.

The last homicide in San Pablo took place Dec. 10, 2012 on the 1800 block of Powell Street and left a girl orphaned. Her parents, Edgar Canpano and Blanca Arguetta, were gunned down inside an apartment about 12:45 a.m.

Additional information about Thursday's fatal shooting was not immediately available.

Anyone with information on the incident is asked to call the San Pablo Police Department's investigation unit at 510-215-3150.

Staff writer Katie Nelson contributed to this report. Contact Natalie Neysa Alund at 510-293-2469. Follow her at Twitter.com/nataliealund.