The Brief Dion Thompson was sentenced to life plus 33 years in prison for murder on Wednesday. Tony Mason Jr., in Baltimore in 2017, when Mason was off-duty. The man convicted of killing an off-duty Metropolitan Police sergeant in 2017 was sentenced to life in prison on Wednesday. Life in prisonWhat we know:A judge sentenced Dion Thompson to life plus 33 years in prison for the 2017 murder of MPD Sgt. MPD sergeant killed in BaltimoreThe backstory:Mason was killed in November 2017 while off-duty in Baltimore.