Virginia is offering probation departments a suggestion for Halloween night: Keep sex offenders home with their porch lights off or have them report to a government office until children in costumes are off the streets.

It's part of a program known as "Trick-nor-Treat," quietly begun three years ago. State officials say that they have no evidence that sex offenders cause problems on Halloween but that the monitoring is needed to protect the public from any potential abuse.

If they choose to participate, probation departments can haul sex offenders to a meeting from dusk until about 9 p.m. or require them to stay home with the porch lights out and not hand out any candy. "We are trying to ensure no new victims during a high-risk time when youth are in the community trick-or-treating," said Larry Traylor, a spokesman for the Virginia Department of Corrections. "We're trying our best to keep the public safe."

Civil liberties advocates, while acknowledging that the program is legal, have a different view.

"It's an unsavory abuse of power, a roundup and temporary incarceration of people based on their past without any suspicion of wrongdoing in the present," said Kent Willis, executive director of the ACLU of Virginia. "This smacks of gimmickry more than sound criminal justice policy. Children are more closely supervised on Halloween than any other night of the year."

In Northern Virginia, Prince William County, the only local jurisdiction participating, will hold a meeting for the approximately 80 registered sex offenders living in the county, Traylor said. Winchester chose the "lights-out" option.

The program is the latest in a growing movement to monitor post-conviction sex offenders in Virginia. In 1999, the state put its sex offender registry online, and last year, state officials funded a program that allows the state to seek civil commitment of sex offenders after they serve their term.

To date, 11 sex offenders, including one from Prince William, have been ordered by the courts to serve additional time at a state mental treatment facility, said Tim Murtaugh, a spokesman for Virginia Attorney General Jerry W. Kilgore (R). Kilgore's office is seeking the detention of 19 more paroled sex offenders.

Murtaugh said the Trick-nor-Treat program, first reported in the Potomac News yesterday, "is a benefit because it protects the public, and it should be seen as an avenue to also protect the offenders by preventing them from having access to children.''

Traylor said the meetings that will be held Sunday night in Prince William, Virginia Beach and in Petersburg south of Richmond will consist of presentations, educational classes and question-and-answer sessions. "It's just another opportunity for treatment and supervision, for them to talk about their case or their particular situation," he said.

Probation officers will be ready to administer drug tests at the meetings if they suspect someone is using drugs, and they will visit offenders required to stay at home. If the offenders don't show up for the meetings or are not at home, their parole may be revoked, Traylor said.

Virginia officials and civil liberties groups said they knew of no other state except Michigan with a similar program. Traylor said Michigan officials got the idea after Virginia officials made a presentation there.

In Virginia, 12,820 sex offenders are listed on state's registry, with 10,627 of those being violent offenders, said Lt. T.W. Turner, a state police spokesman. The list is patterned after Megan's Law registries widely used nationwide and named for a New Jersey girl who was killed in her neighborhood by a repeat sex offender. It does reveal how many offenders' crimes involved minors.

Asked if Virginia sex offenders are known to cause trouble on Halloween night, Traylor said: "I have no evidence of that." He could not specify what prompted the program but said it has been used mainly in the Norfolk area.

Last year, probation department divisions in Prince William, Petersburg and Norfolk were the only state divisions that held meetings on Halloween night, and more than 280 offenders attended, Traylor said. He was unsure how many would attend this year and declined to say where the Prince William meeting will be held.