Yep, exactly. The worst thing Bernard Goetz ever did was turn himself in. A Bronx jury eventually found a $43 MILLION dollar judgement against him. Get mugged twice, with the city doing the biggest mugging.
The police are never there to help just plain old YOU. They are there to enforce that laws and policies that their government choose.
In this place, NYC, the very last thing you want to do is deal with police after having shot someone, whether legally or not. My advice is to hop in your car leaving the immediate area with your lights off and drive like you stole it.