calvin goddard most famous invention was the comparison microscope. witch has solve many challenging cases including the Sacco and Vanzetti Case and The St. Valentines Day Massacre.the microscope is used to compare specimens side by side. The microscope could be used to view markings, hairs and fibers but since Calvin specialized in ballistics, the microscope was mostly used to analyze bullets, bullet casings, and bullet shells. calvin goddard was also asked to lead the first independant forensic science crime laboratory at Northwestern University in 1929.