Yep, and tax fraud, whatever. But there are a lot of violent criminals in jail.
Anyway, usually a prisonner can't be let out on parole unless they have a job lined up for them. Prison employees can find them, there are employers out there who readily accept cheap laborers.
But I am strongly against capital punishment (someone mentionned it earlier). It costs millions of dollars to execute someone - and frankly it's an easy way out. Of course, death row itself is not pleasent. Sitting there for years, just waiting to be kiled *shudder*. But yeah, prevention is majorly the key.