According to The Counted, 198 out of the 1000 killed by police this year were unarmed. Presumably, some of those unarmed people were also attacking cops.
What the cops tell you is a terribly unreliable information source. Check some history:
http://www.mediaite.com/tv/fox-legal-analyst-planting-weapons-on-victims-used-to-be-standard-operating-procedure/"Fox Legal Analyst: Planting Weapons on Victims Used to Be
‘Standard Operating Procedure’":
“When I was in the DA’s office in the 80s and 90s, that was standard operating procedures,” Aidala said. “Police officers — I hate to say this — would keep a second gun that nobody knew about on their ankle, so if they ever killed someone they shouldn’t have they would take that gun out –”
After that the Fox host Brian Kilmeade quickly tried to shut him up with a handwave "such things obviously don't happen anymore because people have iphones!". Yeah, clearly we live in the enlightened days when no cop would stoop to planting a gun on a victim, not like those wild west days of 15 years ago! The basic story is that it was well known at least until the 1990s
if not still ongoing that the police would steal guns from busted drug dealers and the like, then not register them. These guns could then be used as the polce officer deemed expedient, when they either accidentally killed someone with their service revolver they could plant a gun on the body, or they want to shoot someone and not have the ballistics match their service revolver.
And you have
cops caught on camera doing it now, except they're lazy now and shoot someone in the back then toss their taser on the ground and say the black man stole it.
In other words, official police data is basically the
least plausible source for this information rather than the "final word on the matter". The police have a really, really bad history of fabricating this type of evidence. It's basically their career at stake, and they all back each other's stories up. Any time someone can personally benefit from a specific thing, you should look for indepedent information.