It honestly depends on how you spin it. As long as you don't outright say **** the police or something to that degree I think you are okay. If it is a particularly interesting story I think it might help you out a lot by making you stand out.
First two sentences sound interesting and appropriate. If you flesh it out with anything that sounds like the rest of your post, no. Can you talk about it without relating it to the anti-police movement?? If so, being an EMT in riots interacting with the community sounds great. The bones will be in the soup as they say (meaning you gave me the bare bones of your essay but the rest of the meat in the pot will determine if it's good)