HONOLULU — A former soldier who was stationed at Schofield Barracks has pleaded guilty to sexually exploiting a child.

Christopher Ernest Fox entered his plea on Tuesday to the charge involving a 13-year old British girl he met on social media.

Fox was arrested last year. He originally pleaded not guilty to five charges, but changed his plea as part of a deal. Prosecutors agreed to drop charges of obscene material to a minor, cyberstalking and distribution and possession of child pornography.

Prosecutors say Fox began messaging the girl on Instagram and Snapchat in 2016.

Prosecutors say Fox persuaded her to send naked photos by threatening to reveal secrets if she didn’t comply.

The girl eventually notified Wiltshire Police in England.

Officials said Fox was discharged from the U.S. Army last December.