Couple of things I know people won't like but I feel would motivate some people to behave differently.

1) If convicted of a felony using a gun, a sentence of ten years not two under state law for the gun charge separate from the sentence for the actual offense.

2) A parent responsiblity law which could require the parent of a minor child to do jail time along with the minor to be decided on a case by case basis.

The reason for this is because of the feeling that if you put harsh enough penalties in front of people, they will become accountable for their actions over time. After a few people have been made examples of, the rate of such crimes should drop. One reason public executions were common in the days of the wild west was that people could see justice being served, but also it send a message that this is how you could end up if you steal that horse or rob that bank.