You do realize that there are other "high profile" cases that happened after the Michael Brown incident, right? Kaepernick began his peaceful protest after the death of Philando Castile...but there was Freddie Grey, Sandra Bland, Akai Gurley, Tamir Rice, Alton Sterling, & Eric Garner among others.
"Roughly 135 cops died in 2016, making it the deadliest year for police officers in at least five years, Fox News has
found. While there were fewer deaths in 2017, the numbers weren’t much better: A total of
129 officers died last year. And 46 of those were caused by gunfire."
NONE of these were high profile.