Campos and his girlfriend Felicia Sharp, 17, were arrested in Mexicali, Mexico after a four-month manhunt. Campos was charged with Rios' murder and is now being held in on $2 million bail.
While the fugitives were at large, Hemet police arrested Campos' stepfather and mother, Jose and Maria Seym, on Dec. 3, on suspicion of murder and accessory to murder following a Dec. 1 search warrant.
They were released when the Riverside County district attorney's office did not file charges in a 72-hour window following their arrest.
Prosecutors say the case remains under investigation.