A Pearl Harbor officer who pleaded guilty to possession of child pornography will be sentenced on Jan. 20.

Navy Cmdr. James Mattingly, 38, pleaded guilty before federal District Court Judge David A. Ezra on Sept. 18.

A grand jury indictment said he "did knowingly possess matters, including various computer media and hard drives, which contained visual depictions of minors engaged in sexually explicit conduct."

He was released on $25,000 bond.

Prosecutors alleged that he kept the images obtained via the Internet on his personal computer in his Hawai'i home.

His attorney, Brook Hart, said the officer has "some psychological problems" but added that "he is a responsible and trusted officer with an excellent record."

"This is a very sad situation involving an officer who's been an excellent Navy officer and who has had no other deficiencies," Hart said in an interview. Mattingly "is taking responsibility for having possessed child pornography."

Mattingly's arrest came as part of a larger federal nationwide investigation into the possession and sharing or selling of child pornography. "It wasn't just him. There were hundreds and hundreds of people who were investigated by the government," Hart said, adding, "he didn't trade it or send it or distribute it or have any contact" with minors.

Mattingly has been assigned to the U.S. Pacific Fleet in Pearl Harbor since June 2007, according to the Bureau of Naval Personnel.