FARGO, N.D. — A convicted sex offender from Minnesota was arrested in Fargo after posting on Facebook that he’s engaged to a 14-year-old girl and planned to marry her, authorities said.

Tyler Howard Graening, 20, is charged with three counts tied to the case.

The charges are one count of Class A felony gross sexual imposition, one count of Class C felony failure to register as a sexual offender and one count of corruption of a minor, a Class A misdemeanor. He has no recent address listed.

West Fargo police Detective Derek Cruff began investigating Graening after he failed to register as a sex offender in North Dakota, according to court documents. On Graening’s Facebook page, Cruff found what a police report describes as several posts about Graening’s relationship with the teenager, including that they were in a complicated relationship and were engaged to be married.

During a police interview with Cruff, the 14-year-old told said she and Graening had been in a sexual relationship and that at one time she believed she was pregnant, according to the report.

A witness told Cruff he had been in a West Fargo hotel room with the girl and Graening when they were having sex.

Graening is in custody in the Clay County Jail awaiting extradition.