PEABODY – A suicide victim found in a Peabody motel last month was a key player in a Dover, N.H. murder last August, authorities say.Peabody and State Police found the body of former Lynn resident Roy Saunders in a Peabody motel April 15, overdosed on drugs, lying next to a note and a letter.Saunders is the father of 26-year-old Derek Saunders of Byfield and also formerly of Lynn, who along with his roommate, 40-year-old Scott Mazzone, are charged with the murder of Dover resident David A. King.Both Derek Saunders and Mazzone pleaded guilty to murder charges in Strafford County Superior Court Friday, but many questions still surround the murder, including the role of Roy Saunders.According to authorities, Derek Saunders and Mazzone burst in to King’s home on Aug. 29, shooting him twice in the head with a rifle and leaving him for dead on the basement floor.Both men had ties to King and had lived in his basement at different points, but perhaps the closest tie was that of Ron Saunders, who was once married to King’s girlfriend, Dianna Saunders, also a former Lynn resident.Neighbors told police that King and Dianna Saunders were planning to move to Texas with their children, but they do not know if that was a motive for the killing. Police say they do not know where Dianna Saunders, who also lived in Lynn at the time she was married to Roy Saunders, is currently living.Both New Hampshire and Massachusetts state police had been tracking the elder Saunders at the time of his suicide and New Hampshire authorities say they did question him in the murder case, although they declined comment as to what they spoke to him about.Mazzone is facing 33 years to life in prison, while Derek Saunders will face 20 years to life for the killing.