About 3 1/2 years in prison is the sentence for a small-town doctor in northern Minnesota who tried to suffocate his 10-year-old foster son by jamming a latex glove into the boy’s throat.

Dennis J. Sullivan, 51, of Benedict, pleaded guilty Friday in Hubbard County District Court to first-degree assault and immediately sentenced to three years and seven months in prison, the term called for by state guidelines.

According to the criminal complaint, Sullivan’s wife went into the boy’s room on the afternoon of June 17 after hearing a strange sound. She said she saw her husband pushing his fist, covered by a latex glove, down the boy’s throat. Sullivan pulled the glove out and put it in his pocket, his wife told investigators. She asked Sullivan what he was doing, and he said he “did not know.”

Sullivan was arrested later that day in Grand Forks at a mental-health clinic.