DURHAM – A misunderstanding of the law led to Ronald Leno’s failure to register as a sex offender when he moved to Maine two years ago, concerned residents were told at a meeting Thursday night.

Leno, 56, asked whether he was required to register, but was told he did not have to, said Detective Bill Gagne of the Androscoggin County Sheriff’s Department, who chalked up the error to a “misunderstanding” of the law.

Police have said they learned Leno was living in Durham when a woman filed a complaint against him with Brunswick police.

Leno was charged with aggravated assault after a weekend altercation with a Durham man who was upset to learn the convicted rapist had been speaking with his wife.

Leno was being held Friday at the Androscoggin County Jail on $20,000 cash bail, or $50,000 in property. A probable cause hearing is set for July 20.

One of the 250 people attending the meeting declared she wouldn’t hesitate to use a gun to protect herself if Leno came onto her property.

But a man who said Leno had done the “most despicable” things to his 17-year-old daughter advised people against taking the law into their own hands.

“I’d be in jail today if I followed my heart,” said the man, who identified himself as “David from central Massachusetts.”

Leno’s criminal record includes three rape-related convictions in 1978 and 1980 in Massachusetts and Hawaii, convictions for theft, assault and drunken driving, and parole violations. The decorated Vietnam veteran has lived in Maine for more than two years, his lawyer said.