LOS ANGELES – Fifty-five men, including a sheriff's deputy and at least one attorney, were charged with possessing child pornography following an eight-month investigation, authorities said Tuesday.

The U.S. attorney's office in Los Angeles said the suspects used peer-to-peer networks to exchange graphic images and videos, then stored the files on their computers.

All were charged with possession of child pornography. Some had been charged with additional offenses, such as production of child pornography and committing crimes while registered sex offenders.

Those facing charges include San Luis Obispo County sheriff's Deputy Bryan Jon Goossens and attorney Thomas Merdzinski of San Bernardino, said U.S. attorney's office spokesman Thom Mrozek.

A man who identified himself as Merdzinski hung up the phone after being asked for comment by The Associated Press.

Messages left for Rob Bryn, the press information officer of Goossens' department, were not immediately returned.