Ah yes, no need to look at questions like socioeconomic causes, psychological issues or the failure of the prison system at rehabilitating people.

Just lock them up indefinetly. And then what is now considered the medium persistency group can be split into a new high persisting and a smaller medium persisting group. What to do then is obvious. You must permanently lock away the new high persistency group. Just rinse and repeat until a large part of the population is in prison and the economic and social consequences of having so many people incarcerated will cause crimerates to spike as people need to survive in a dysfunctional society. Luckily we can just lock up these people too, until the entire country is imprisonend.