Platt would have been dead in short order but the 9mm just did not have the power to do the job. One in the heart and its lights out in short order. a .40 would have put a hole in his pump.
Colt King Cobra .357 Colt Anaconda .44mag
Springfield Armory .45 Double stack Loaded
XD40 service XD45 Taurus 617 .357mag
Smith M&P 40