Should be “underappreciate,” not “underestimate.” Apologies again for the misquote.
According to the Guardian (upon whom, like all mainstream news media, always, take care to keep a wary eye): “Deaths in police custody since 1998: 333; officers convicted: none.”
Edited to add: Apologies for the misspelling of Brown’s name. Also for the misquote: he said “underappreciate.”
(Unrelated: Simeon is the name I love most in the world. Not hard to figure out why, if you think about it.)