Our system doesn't protect human rights equally.  Not by a long shot.  In fact, considering our wars in the middle east, we're arguably the worst at it.  Internally, we still have an inequality in justice as well.

The DA is expressing an opinion and maybe trying to warn us that the system isn't working.  Given the recidivism rate, he has a valid point.  Now, staying in our jails for 24 instead of 9 years might not make a hoot of difference, since our jails are flawed from the start.  But, maybe it's better to err on the side of keeping him off the street to protect those without his prior (and possibly present) issues.