I’d bet it’s 10,000 to Ø.
According to their site, there have been 749 police deaths from the beginning of 2009 to date. There have been 70 this year, 28 of which are “fire arms related,” up from 17 YTD the previous year. I think friendly fire would be included in this category.
Total shot and killed over five and a half years—likely between 200 and 300—after one knocks out friendly fire, it wouldn’t surprise me if cops have shot and killed more innocent or helpless people over the period than cops shot by non-cops.