If you want to stop ganking, well answer one is you can't, since someone has to die to set off the chain. But, you can make a criminals life harder by accruing more and more heat that
does not go away.
We have weak sauce BH come after you, who need to be engineered and come in large numbers. They need to be annoying and a threat to work.
We need ATR that are persistent, and that follow you. I suggested this:
A half though out idea, but: If a player is at notoriety 10, they have to be very careful about being scanned by random ships, security or other players as if they are, an ATR security vessel drops in to hassle them. The handwavium being that a scan is like a sighting of you thats disseminated...
forums.frontier.co.uk
What this does is remove a killers shields wherever they go and are detected (but can be avoided with skill- i.e., if they lay low and stay away from trouble).
Lastly its on the individual to do as much as they can to be safe, 'git gud' is not an insult, but advice. Build better, fly smarter.
Notoriety has to act as a modifier, in that by being naughty it shuts you out of 'polite society' and opens up places like anarchies. Imagine there are systems that have roving bands of pirates in G5 ships, and the only way to get them to avoid you is to be feared via notoriety 10, 20 etc. In this way players who kill are encouraged away from law abiding systems which have the roving ATR on scan (as done above).
I really hate artificial clauses and would love something more organic like this, where the way you play shapes how the galaxy reacts to you that at the same time allows the norms to be protected but still allows killing.