Former Prince George's police Officer Keith Washington lost an appeal to overturn his involuntary manslaughter and first-degree assault conviction.
Washington was sentenced to 45 years in prison for killing one furniture delivery man and wounding another.
The incident happened in January 2007. Brandon Clark and Robert White were making a delivery from Marlo Furniture at Washington's Accokeek home.
A confrontation followed. Washington shot and killed Clark and wounded White. Washington claims he acted in self defense after the men attacked him.
After his conviction, Washington's lawyers appealed on the grounds that the trial court should have admitted evidence of White's 11 past criminal convictions. On Friday, the Maryland Court of Special Appeals in Annapolis rejected that argument.
Last week, a Prince George's County judge threw out a civil suit filed by relatives of White and Clark.
