RIVERTON, Wyo. (AP) — A Wyoming man has been sentenced to 65 years to life in prison for the death of his 3-month-old son.

Paul Miller was sentenced Wednesday for the August death of his son Hunter, who suffered blunt-force trauma and a skull fracture. Miller pleaded guilty in January to second-degree murder.

Prosecutors say he hit the boy while trying to calm him. Hunter had been born severely premature and weighed only about 8 pounds at the time of his death.

Miller told detectives the death was an accident and he didn't know how to care for Hunter. But the boy's mother, Tasha Croak, said they both met repeatedly with doctors and nurses after the premature birth.