Starting this weekend, it’s going to be a little harder for convicted sexual offenders to keep their past crimes a secret.

On Saturday, a new state law went into effect requiring anyone sentenced for sex crimes as far back as 1982 to register on the state’s Web-based Sex Offender Registry. Until now, only convictions back to 1992 were included in the online database.

The expansion could add about 500 names to the current list of about 1,600 people. Unfortunately, the new registration requirement depends upon compliance by the offenders themselves, which could limit its effectiveness. The state hasn’t tracked the whereabouts of past convicts unless they’ve run into other trouble with the law. Information for many of them – 23 years old in the most extreme cases – is outdated and useless.

Maine’s efforts to expand its online sex offender registry track with public interest and with national efforts to crack down on sex crimes, especially those with child victims. But the teeth behind the law are much less sharp.

Last week, the U.S. House of Representatives passed legislation that adds new mandatory punishments and monitoring requirements to child sex offenders. The bill, if it becomes law, would create a national Web site similar to Maine’s. Failure to register would carry a possible 20-year prison sentence. In Maine, failure to register is a Class D crime, which carries a maximum sentence of one year, for the first offense. A third failure to register is a Class B felony, with a possible prison sentence of five years.

If the state really wants to force sexual criminals to register, following the feds with harsher punishments might compel hard-to-find convicts to come forward instead of risking a long haul behind bars.