Action News broke the story in December when Scarber's father -- assistant CHP chief Kyle Scarber -- reported his son missing on the day Spencer was supposed to testify in his own defense. But detectives determined the disappearance had been staged.
A camera at the Mexican border caught an image of a family car crossing the border into Mexico just after 3 a.m. that same morning.
Spencer's mother and sister used their passports to cross back into the U.S. on foot just before 5 a.m.
Detectives say Spencer Scarber was using an alias when he was arrested in the Acapulco area. Sheriff's deputies have also arrested Kyle Scarber and his wife, Gail, for helping their son escape justice.
Stay tuned to ABC30 and abc30.com for updates on this story.