LEWISTON – The Maine sex offender registry will expand with a new law that requires people sentenced for sex crimes back to 1982 to put their name on the list.

The extra decade’s worth of offenders – the previous law dated back to 1992 – could add about 500 people to the registry, according to one early estimate. But tracking down those people will be tough – people die, people move and the old records are mostly in paper form.

“Good luck in finding those people who lived at P.O. Box 512 in Hartford, Maine,” said attorney Walter McKee, president-elect of the Maine Association of Criminal Defense Lawyers. “Go ahead and try to find them and bring them in [to the registry].”

Maine has had a sex offender registry for six years. It is posted on the Internet and is the state’s most-popular Web site, getting more than half a million hits a month.

People convicted of sex offenses appear on it for 10 years, and those convicted of sexually violent offenses stay on for life.

The registry’s last major expansion came in 2002, when the Legislature reached back to include people sentenced since 1992. Then, the state had to go through 10 years of records, cull the sex offenders and contact them to get them to comply with the law.

This time the law, which went into effect on Saturday, will require going back 23 years, into a pre-computer era.

While the intent of reaching back to publicize past offenders “is for the right reason, it’s just difficult to achieve,” said Ruth Lunn, a supervisor at the State Bureau of Identification.

On paper, Maine has records of 375,000 people charged with crimes since 1937.

Since the Bureau of Identification started creating electronic rap sheets in 2002, 141,000 of those records have been entered into a computer. Entries occur when a person is charged with a new crime or when someone requests a background check, Lt. Tom Kelly said.

Among those 141,000 names, Kelly said 500 people appear to have committed a sex crime in the 1970s or 1980s that would land them on the registry for life, under the new law.

More research is needed, he said, before notification letters go out requiring people to sign up and submit a photo.

There are no immediate plans to move the remaining 234,000 names from paper to computer so they may be searched for more sexually violent offenders between 1982 and 1992.

“Someone would have to physically pull every record and I don’t know if that’s the best use of time,” Lunn said. “Should we thumb and thumb and thumb?”