Pro MMA fighter Andrew Osborne was sentenced to 25 years in state prison Thursday after he pleaded guilty to first-degree aggravated manslaughter, according to the Atlantic County Prosecutor’s Office (N.J.) . Osborne, 35, admitted he stabbed 47-year-old Brian Wilkinson to death inside an Atlantic City, N.J. hotel room. He must serve at least 85 percent of his sentence in New Jersey State Prison (N.J.S.P.) before potential supervised release. According to a statement from prosecutors , Osborne stabbed Wilkinson in the head and neck at Ocean Casino on Sept