Daniel Martinez, 29, of West Hills, Calif., was booked on suspicion of kidnapping and was being held in lieu of $1 million bail Sunday, the LAPD said.
A statement from the department said investigators "have reason to believe" the primary suspect, Tobias Dustin Summers, 30, could be in San Diego and "may also have changed his appearance by shaving his head."
The men are suspected of abducting a 10-year-old girl from her home in Los Angeles' Northridge neighborhood between 1 a.m. and 3:40 a.m. Wednesday.
She was found, bruised and scratched, about 3 p.m. Wednesday, near a coffee shop about 6 miles from her home, police said.
Police said she told them two men were involved in the attack and that she was taken to multiple locations in different vehicles. She had been sexually assaulted, police said.
Martinez and Summers have extensive criminal records, the Los Angeles Times reported Monday.
Martinez has convictions of burglary, petty theft, grand theft, resisting a police officer and unlawfully entering a property between 2004 and 2012, the newspaper reported.
Dating back to 2002, Summers has been charged with kidnapping, robbery and petty theft. He has convictions for receiving stolen property, grand theft, possession of an explosive and presenting false identity to police.
Los Angeles Police Cmdr. Andy Smith said there is no indication that the abduction was part of a series of kidnappings and that no similar incidents were reported.