OKLAHOMA CITY (AP) — A former Oklahoma state senator accused of engaging in child prostitution and pornography pleaded guilty Thursday to a federal charge of child sex trafficking.

Former two-term Republican state Sen. Ralph Shortey entered his plea before U.S. District Judge Timothy DeGiusti in exchange for federal prosecutors dropping three child pornography charges against him.

Shortey, dressed in a blue suit and wearing a GPS tracking device on his left ankle, said nothing when DeGiusti ordered him back into federal custody pending sentencing. Shortey removed his jacket and tie, and federa...