Do you think there could be some semi-legitimate reasons for that behavior, beyond just laziness and cowardice? Cost is a big issue in the justice system. Of course, you should still go after murders (and other serious offenders), even if it's hard and costly.

At least some of the issues in our justice system stem from not having the resources to handle every case fairly. Every criminal case should be fully investigated and tried in court, but the system would break under these conditions.

So you end up with a highly perverse system based on extortion, and heavily biased depending on socioeconomic status. Sometimes it works "too well", other times it doesn't work at all.