ABERDEEN PROVING GROUND: Former Drill Sergeant Delmar Simpson stood straight at attention as a military juror quickly read the verdict against him: Guilty on 43 of 54 charges, including raping six trainees a total of 18 times. Although 11 other men face charges in the Aberdeen investigation, Simpson's was the most egregious case in the military's worst sex scandal since 1991's Tailhook. Jurors deliberated for five days to return a verdict which ultimately came down to a question of abusing authority: Did Simpson use the sheer power that a drill instructor wields over trainees to intimidate them into having sex? The key ruling of the trial was that Simpson's position alone meant he did not have to physically threaten a female trainee for rape to occur. But threats may have been made: According to Army documents, he told a trainee, "If anyone finds out about me having sex with you, I'll kill you." Defense lawyers contended that women angling for preferential treatment willingly had sex with Simpson and then falsely accused him of rape to avoid prosecution under military law for having sex with a superior. The 32-year-old Simpson, who will be sentenced by the same jury next week, may face life in prison.