SAN MARCOS, Calif. -  

San Diego County Sheriff's deputies have arrested a 21-year-old man who drove his car into a good Samaritan who had tried to stop him from beating his girlfriend.

Sheriff's Department spokesman Daniel Deese says parolee Jorge Colin Alcantara was taken into custody Saturday and is jailed on suspicion of attempted murder.

Deese says Alcantara reportedly was beating up his girlfriend near an intersection in San Marcos on Jan. 21. A bystander intervened and Alcantara drove off, only to return and strike the bystander with his vehicle.

Witnesses say Alcantara got out and began beating the man until several people jumped in and stopped the attack. A tip led deputies to Alcantara on Saturday.

The good Samaritan was hospitalized with serious but non-life-threatening leg injuries. The woman who was beaten was not seriously hurt.