No set number of shots, only when the threat stops.
“After reviewing all the evidence, I believe there can be little serious doubt that P.O. Manney was justified in firing at Dontre Hamilton, who was attacking him with a deadly weapon (baton). The more difficult issue is whether P.O. Manney fired more shots than necessary, or continued firing after he could reasonably perceive that Hamilton was clearly no longer a threat. Police officers in Milwaukee and throughout the United States are trained to fire to “stop the threat”. The 13 or 14 shots fired by P.O. Manney would, in all likelihood, have been fired in roughly 3 to 4 seconds total elapsed time, from first shot to last….
….While, as can be expected, the many witnesses to this event give varying accounts of what they saw and heard, several witnesses with the best, closest views of what occurred have stated that P.O. Manney stopped firing when Hamilton fell to the ground, and Manney did not continue firing after that point.
via Milwaukee officer shoots man 14 times, ruled “justified self-defense” | FOX CT.
I was cured long ago of the “one-shot, one-kill” malady and “stopping power”. Too many cases out there where a bad guy has absorbed amazing amounts of shots and pretty much kept going long enough to make you believe in monsters. In the latest issue of SWAT Magazine, there is a case where the criminal got shot with everything but a mini-gun and still kept coming with the only shot that made him non-threat was a non-lethal hit to the arm that broke the bones and rendered him unable to keep using his firearm.
Go read the whole thing as it is interesting and good info to process.