Strict Utilitarianism leads to some pretty dark places. For example, Utilitarian Peter Singer advocates infanticide for handicapped babies, to "maximise happiness." To invoke Godwin's law, Hitler's methods and goals – eliminating inferior genetics – were quite commendable from a strictly Utilitarian standpoint.

I think Utilitarianism is a good place to start. But like most ideas, an absolutist position ends poorly.

EDIT:

I just realized you might have been asking "How is this policy Utilitarian?"

Utilitarianism is "the greatest good for the greatest number" or some variation thereof. I think this policy is Utilitarian because it says "statistically poor and non-whites are repeat offenders, therefore they should get more jail time." Statistically, this does indeed reduce crime. At the cost of unduly punishing individuals who would not have been repeat offenders, and being unjustly lenient to rich whites.

The "we shouldn't harm individuals for the sake of the group" is definitely a Deontological argument (Deontology is kind of the opposite of Utilitarianism/Teleology and can be roughly summarised as "the end doesn't justify the means").

I am definitely not a Deontologist. But in this case, it seems obvious Utilitarianism is unjust. You can't just put all poor black males in jail because they're statistically more likely to commit crimes.

I'd also note the particular danger of this policy, is that the correlation of recidivism and race+wealth is a step removed from "we should use statistics for sentencing!" Hence my "indirection" comment.