GRAND FORKS - A 30-year-old Grand Forks man has been sentenced to 18 months imprisonment after pleading guilty to having sex with a 16-year-old foster child.

Kerry Allison Knutson admitted to luring minors by computer and corruption or solicitation of minors, both Class C felonies, in North Dakota District Court in Grand Forks on Tuesday.

He was charged with the crimes in February 2014 after a Grand Forks County social worker went to Grand Forks police in December 2013 and told them she believed there had been sexual contact between Knutson and a 16-year-old girl in the custody of social services, according to the criminal complaint.

The social worker also provided police with private Facebook messages between Knutson and the girl, which indicated the two had had sex in the past, the complaint says. Police obtained a search warrant for Knutson’s and the girl’s Facebook accounts, the complaint says.

Their Facebook messages showed Knutson, then 28, had asked the girl multiple times to send nude pictures of herself to him, according to the complaint.

During police questioning, Knutson admitted to having sex with the girl at her foster mother's Grand Forks residence and to asking her for nude pictures, according to the complaint.