The US libel laws are much more publisher-friendly - I cannot legally claim that Oury Jalloh [0] was murdered in Germany (even though he almost definitely was), whereas in the US the accused police has a higher burden in proving he wasn't.
a.) Lots of people appear to be doing it:
https://html.duckduckgo.com/html?q=mord%20an%20Oury%20Jalloh
What exactly do you fear the repercussions would be?
b.) Accusations of a crime presented as a fact appear to be "libel per se" in the US, so quite actionable:
https://legal-dictionary.thefreedictionary.com/Criminal+libe...