AUGUSTA — The final two defendants were sentenced Monday for the drug-related beating death of an Augusta man in 2015, with the state’s attorney saying the sentences reflected the defendants’ early cooperation in the investigation and their acceptance of responsibility. Both Michael “Dirty” Sean McQuade, 47, of Augusta and Damik “Doughboy” Davis, 28, of Queens, New York, pleaded guilty 11 months ago to felony murder and robbery in the killing of Joseph Marceau and signed agreements with the state that spelled out their sentencing parameters. Justice Daniel Billings imposed the sentences recommended by both sides. McQuade was ordered to serve 12 years in prison with 13 years suspended and four years of probation.