The bullet that started things was not .32 caliber, but .380, fired from a .380 caliber (9mm Browning Short) FN Model 1910 pistol, serial number 19074. The four Model 1910 pistols used (numbers 19075, 19120, and 19126 were the others) were bought in a Belgrade gun store by one Major Tankosic, of the Serbian secret service. The major also provided hand grenades to the assassins, but none were used.
Tankosic headed an organization called the Black Hand, what we would now call a terrorist group. Of course, the Black Hand was a phony; it was really organized by the Serbian government to carry out "dirty tricks" the government did not want to acknowledge, such as assassinations.
Jim