BELFAST — A grand jury indicted a Stockton Springs man May 12, on a charge of sexual exploitation of a minor.

Matthew A. Cox, 35, a former Searsport High School softball/basketball coach, was arrested Dec. 15 after law enforcement investigated claims of an inappropriate relationship between Cox and an underage student at the school, according to court documents.

The investigation into the claims began June 3, after a friend of the juvenile reported suspicious texts between the victim and Cox. An interview with the friend was conducted, followed by an interview of the victim.

During the interview the victim told investigators that after initially corresponding via Facebook, beginning in November 2014, the victim and Cox began messaging each other “regularly.” According to an affidavit, this correspondence soon grew to include Cox both requesting sexually exploitative material from the victim and sending inappropriate material to them.

Cox was interviewed by Searsport Police, during which time he requested a lawyer be present, though he did turn his cell phone over to police willingly. Both Cox and the victim’s cell phones were sent to the Maine State Police Computer Crimes Unit for further analysis.

After reviewing content recovered from the phones, and conducting an additional interview with the victim, a warrant for Cox was issued and he was arrested Dec. 15.

Erica Thoms can be reached at news@penbaypilot.com