Johnny and Carol Montanez, both 38, were arrested during a traffic stop on state Highway 4 at Lone Tree Way in Antioch around 8:55 a.m. Tuesday, police said.
Police said the arrest came after an investigation into allegations that the couple was physically and sexually abusing members of their family.
Johnny Montanez was taken into custody on suspicion of sexual assault and is being held in the Martinez Detention Facility on $6 million bail, according to police.
He was charged on Thursday with six felony counts of aggravated sexual assault and one count of child cruelty, according to the Contra Costa County District Attorney's Office.
Carol Montanez was arrested for alleged child cruelty and is being held on $250,000 bail, police said.