You shall all be assimilated ... UFP Style!

Okay, I am back with another imponderable...

The UFP has eliminated want, greed, poverty, etc. With this, one assumes, most crime has also curled up and died. But not all.

(This is hazy memory, so please correct me as necessary!) During the pilot episode of "Voyager" we see that one soon-to-be-crewman has been accused of crimes and wears some sort of tracking-anklet. Imprisonment seems to be passe. Then in TOS we see Garth and the gang in a mental institution under heavy sedation (some might go so far as to call if mind control...).

Given that one guy with a phaser could make Columbine look like a school yard spat and given human (...and other species...) variation, one has to assume that once in a while someone snaps like a bunny and goes postal in the UFP.

So, are the perps "re-educated" a la Garth of Izar? Are they forced to wear little anklets and told not to be naughty again? In other words, how does UFP (as opposed, apparently, to member-planets) deal with crime, criminals, and mental instability?

Information. We want Information...

Reeducated, of course...in a nice, non-hurtful, soft and fuzzy, nerf-world kinda way.

I figure some of the 'reclaimable' are sent off to colonize worlds, where they have no choice but to work together and hence become civilized by creating civilization through necessity

That vague memory from the Voyager pilot is of Tom Paris in a penal colony in New Zealand.
Dr. Bashir's father was to be incarcerated.

Garth and his buds were not just criminals, they wer criminally insane. Like any other insane, they were entitiled to the best treatment the Federation can provide. Like all criminals, their movements must be restricted to protect society.

For criminals I would think that a large portion of their sentence involves qorking for the good of society. From the look of the New Zealand penal colony conditions are pretty good.

Starfleet has stockades for its prisoners. From Ro Laren's experience, they do not appear to be nearly as comfortable.

During the TOS era, they seemed to assume all crime was the result of a mental disorder. In "Dagger of the Mind", we see an asylum where attempts are made to cure those with mental disorders that make them dangerous. On Elba II ("Whom Gods Destroy"), the colony is described as where "the fifteen remaining incurably insane" patients are interned. Presumably, until they can be cured or they die.

During the TNG era, at least some criminals are simply locked up. As has been pointed out, this is what happened to Bashir's father for having his genes resequenced.