Pablo Escobar says hi:
High-security should mean that an area has both enough crime, and enough assets to protect, to justify the cost of maintaining rapid response forces capable of being a credible deterrent and possibly even stopping a crime in progress.
Using reality as an analog, it doesn't matter how high the security is somewhere, if I want someone dead badly enough, chances are they will die. When every second counts, help is minutes away. The reason there isn't considerably more violence and chaos in places with effective security is that the consequences are extreme. Yes, I could stab, shoot, run down with a large vehicle, or stuff my van with a ton of homemade explosives and five hundred pounds of tungsten ball-bearings and kill just about anything...but the chances of me doing this in a 'high security' area, and escaping are negligible. If I want to survive, freedom intact, as a killer, I need to target nobodies, or ambush people where response times are long, witnesses few, and surveillance absent.
Elite: Dangerous is too soft on consequences. There is no crime prevention system, and no credible deterrent, because of this lack of consequence. There is no way to make an ATR response swift and potent enough to actually protect anyone as long as CMDRs inclined to attack clean targets can be clean while doing so and ATR, as ineffective as they are, already have absurd and immersion defying capabilities (weapons no CMDR can get a vague analog to and the ability to teleport).
Waiting for criminals to act is acting too late, but deterrents need to be as proactive as possible, because making them heavy handed like ATR is both ineffectual and implausible. Unfortunately, the game is completely lacking in the mechanisms (mostly persistence related) to do credible C&P.