Police identified the dead as Mark Courtney , 33 , of Leonardtown ; Daryl Wills , 38 , of Clinton ; Maycol Lopez , 20 , of Gaithersburg ; Blaine Briscoe , 49 , of La Plata ; William Gaines , 61 , of Nanjemoy ; and Craig Simms , 37 , also of Nanjemoy .