All the previous school shootings, Waco, JFK, MLK, Scalia, Breitbart, Seth Rich?
And so so many others:
The process server at Democrats office in Washington DC
The 3 attorneys in Florida
Plus all the missing children, teenagers etc... The UN guy, the Haitian guy, the weightlifting guy, the drowned cop from the Potomic river, the Washington DC car firm guy, and many more.
Probably can't discount the Alfred Murrah Building, OK City. Lots of controversy and unanswered questions there.
See: Michelle Malkin, Murrah.