Parole officers conducted compliance checks with more than 1,700 convicted sex offenders Wednesday night as part of "Operation Boo," the Los Angeles Times reported.
More than 50 parolees were arrested in Los Angeles and other Southern California counties, the California Department of Corrections and Rehabilitation said.
Officers seized child pornography, drugs and weapons.
The state has conducted an annual Halloween enforcement operation for nearly 20 years.
Swim Week Miami Beach 2014 [PHOTOS]