We should be taking a hard look at the practices of the prosecutors and judges. If somebody is arrested for something substantial multiple, then the prosecutor should be obligated to not offer a plea bargain, but instead go for maximum penalty.
It might do some good to publicize some statistics on prosecutors relating to how many times a "customer" is re-arrested after plea bargain, and on judges who give skimpy jail terms to repeat offenders.
BINGO!
Since judges are mostly elected, publishing their records as to if they are hard or soft on crime before the primary and full election would do a lot.
Similarly, tracking individuals within the prosecutors office as to how tough they were on crime, and stopping some of the "plea bargaining" for career criminals would be a good idea as well.
too many criminals are getting arrested, and then let go, by a system that wants to be "gentle and fair. Oh, well.
It's not so much that they want to be "gentle and fair", as that people, including government employees, tend to respond rationally to the incentives of their system.
If prosecutors are judged by convictions, then they have an incentive to plea bargain in order to get any sort of conviction in minimal time.
Plus they have no incentive to put away career criminals, since more crimes and arrests mean more worthless convictions and more case load justifying a bigger budget and staff.
To really cut back on crime, the people must recognize that most crime is committed by a relatively small number of career criminals, and change the criteria that prosecutors and judges are evaluated upon accordingly.
We also need to have it be the case that when a productive citizen shoots a career criminal, then that citizen is automatically given the benefit of the doubt as to the necessity for the shooting, and granted immunity from lawsuits.