Whenever the Legislature starts playing around with mandatory 100-year prison sentences, it's time to wonder whether there's some over-reacting going on. That's especially true when the targets of such a bill - child molesters - are so universally despised.

But in this case the legislation in question, Senate Bill 547, is hardly an example of a thoughtless, runaway reaction to a hair-raising crime. Instead, it is a bill carefully prepared by a special subcommittee from three other bills and a Florida statute, "Jessica's Law." It targets adults who attack young children, and ensures that the 100-year sentence only applies to the worst of the worst - the very people most likely to offend for as long as they live.

The measure, introduced by Sen. Gary Perry, R-Manhattan, was given preliminary approval in the Senate Monday by a 49-1 vote. It would apply to those designated by a judge as sexual predators of children - someone 18 or over who attacked a child 12 or under - and the 100-year sentence could be imposed only if at least one of these criteria was met:

- The offender was a stranger to the victim.

- The offender had established a relationship with the child solely to molest the child.

- The offender committed another forcible felony while committing the original crime.

- The offender compelled the victim to submit by force.

Generally speaking, mandatory sentences are bad news. They steal important discretion from the judiciary and fill prisons with nonviolent offenders. But, given the horrible record of so many convicted child violators - and killers - who apparently really can't stop offending, Perry's bill is a reasonable and appropriate response.