I'm not there seeing it first hand, so this is all theoretical. But it's generally accepted that certain crimes are rarely deterred by threat of punishment. Also, many law enforcement agencies seem to have a split personality about whether their primary value is deterrence, prevention, or investigation.

If crime isn't generally deterred by police presence, I don't know that you can blame a large increase in crime on lack of policing. That said, any police that express - through word or deed - that they're intentionally permitting crime to prove a point to those who support changes, should be fired immediately. Police should never be seen as more than a necessary evil.

If it's genuinely 15% of the population have gone feral, you need about the same proportion to be policing them. I don't think it's reasonable to expect to solve that level of societal problem with more policing. Something else has gone badly wrong in a society that has that level of problem to solve.