The thing with leftist societies after the tipping point is passed (e.g., California) is that nobody has to pressure anybody.
What are the chances that the LA coroner is a believer in The Revolution?
Pretty damn good. And what are the chances that if he finds evidence of foul play that he will tell the DA, who is almost certainly a true believer?
Near zero.
You don't even have to go that far. What are the chances he gets a bit of advice that it is better this way and to keep his mouth shut? He's already got a dead guy laying on his table --that's all the persuasion most would need.