Deputies with the special enforcement team at the Perris station served a search warrant at a home in the 2800 block of Pinta Court on Tuesday.
Amid the search, investigators found stolen mail, checks and credit cards as well as four ounces of methamphetamines.
Juan Carlos Valencia, of Fontana, was arrested for possession of meth for sale, possession of stolen checks and receiving stolen property. A 16-year-old boy who was also at the home was arrested on suspicion of being under the influence of meth and possession of a loaded gun.
Valencia was booked at Southwest Detention Center in lieu of $50,000 bail, while the teen was booked at Southwest Juvenile Hall.
During the investigation, a majority of the stolen mail, checks and credit cards were found to belong to Erica DeLeon, a 28-year-old Moreno Valley resident.
Riverside police officers had arrested DeLeon on Feb. 24 on suspicion of fraud. She remained in custody at Larry Smith Detention Center in lieu of $150,000 bail.
The investigation was ongoing.