Prosecutors say 25-year-old Jonathon Deegan and 54-year-old John Deegan had illicit material on their personal computers. The two share a home in Long Beach.
The Deegans turned themselves in on Oct. 5 and were released on their own recognizance. The elder Deegan, a 20-year veteran patrol officer with the LAPD, is set to face trial Dec. 1. He's been on paid administrative leave since March.
The head of the Los Angeles police union expressed shock last month at the officer's arrest.
"While the arrest is embarrassing to the men and women of the LAPD and the city, our message to the community is unequivocal: Anyone who does anything that might endanger the welfare of a child has no place in the LAPD," said Los Angeles Police Protective League President Paul M. Weber.
Jonathon Deegan will be sentenced in April.
City News Service contributed to this report.
