my assumption from reading around is this Rashan Charles was a scumbag dealer in grade A, police tried to apprehend him for being a scumbag dealer, he attempted to flee and like many dealers swallowed the wraps of heroin (or what ever drug it was) to A) conceal evidence, B) **** it out or puke it up later so he can continue being a scumbag dealer.
Now he probably died due to choking on these wraps whilst being apprehended after fleeing from the police. Just like the guy a few weeks ago Edson Da Costa whose death also sparked protests is very likely a dealer too who had swallowed packages whilst being apprehended by the police (likely died due to them too)