Bounty hunting in a RES is not without risks, but when you become experienced at it, you should never be killed by the Feds after you mess up. Firstly, you need to be attentive to any messages that say that you've been charged with assault or murder. The moment you see one, you must turn around, put 4 pips to engines and boost away from the feds and up into the sky clear of the rocks. You must keep 4 pips to engines all the time and the other two to shields. After hitting the first boost, put your weapons away. Make sure that you're travelling at right angles to the plane of the rocks. As soon as you're clear of mass-lock, engage your FSD into safety.
You should have 100% success rate using this method, even when using the basic Sidewinder. There's a couple of things that will help with your success: Firstly, you must react quickly. The aim is to get far enough away from the cops on the first boost so that their weapons can't do you any harm. If you delay, you'll be taking heavy fire. Secondly, speed is more important than shields, weapons, jump range or anything else when you're in this situation, so always make sure that you have the best thrusters and power distributor you can get before thinking about any other upgrades.