A federal rule change is pushing Maine legislators to make improvements to the state’s sex offender registry that they have so far been unable to do on their own. Differentiating between the most dangerous offenders and those less likely to commit another crime will make this information more useful to communities while not exposing those on the online registry to unnecessary risk.

Clearly describing the crime committed and the accompanying sentence would also improve the value of the Web site, the most popular in state government.

In 1994, Congress required states to register sex offenders and revised the law in 1996 to make the information available to the public. Since then, all but four states have created online registries. Maine is among the 31 states that include offenders’ photographs and addresses on the Web site.

Although the crimes offenders were convicted of are listed, they are described in technical terms that require linking to state statute to get information about the severity of the crime and the accompanying punishment.

Under a law passed by Congress last year, states must have a tiered system that separates the most dangerous from lower risk offenders. If states don’t comply, they can lose federal funds for law enforcement.

Differentiating between high- and low-risk offenders simply makes sense.

Putting the mug shots and addresses of all the state’s registered sex offenders on a Web site is a convenient way for the state to believe it is meeting a public reporting duty. However, this approach raises the larger question of whether the registry is meant to be part of an offender’s punishment.

If so, should that punishment be the same for all offenders no matter the severity of their crime and whether they have just one or repeat convictions? Now an 18-year-old who had consensual sex with a minor girlfriend is treated the same as someone who has repeatedly raped young children.

Maine lawmakers are looking at Massachusetts’ registry as a possible model. Massachusetts has a three-tiered registry, with only the information about the highest-risk offenders available to the public online. Information about the lowest-risk offenders is not available to the public and that for those in the middle category can only be obtained through a phone call.

None of this stops local law enforcement from notifying residents when a sex offender moves to town.

But it answers the question of why anyone, anywhere should have access to information about all of Maine’s 2,700 sex offenders, some who were convicted of a single crime 25 years ago. A Nova Scotia man used the online information to track down and murder two men listed on the state’s Web site.

Differentiating between offenders doesn’t excuse in any way the crimes these people committed, but it says that if the state is going to take action against citizens, which it does when creating an Internet sex-offender list, it has a duty not to endanger them.

Changes that move Maine’s system closer to that balance would be welcomed.