Both the FBI and CA DOJ produce an annual report summarizing LEO fatalities and injury stats for law enforcement agencies. The FBI's document is quite detailed statistically and the CA one gives brief descriptions of each incident. I don't know if they are available to non-law enforcement personnel and I really can't think of a reason the reports would be restricted. You might try contacting the training or PR officer of your local agency or FBI field office.
I believe the state of Minnesoate does the same and their report used to be published on their state's DOJ site. I had a URL once and if I find it I'll post it.
I'm not aware of any database covering non-law enforcement engagements.
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