Lawmakers in Montpelier yesterday reached a tentative agreement on prison sentences for first-time child rapists and other violent sex offenders, paving the way for a significant overhaul of Vermont's sex-crime laws.

Under the compromise, which passed 6-0 yesterday in a House-Senate conference committee, judges would be required to hand down 10-year sentences for first-time offenders convicted of aggravated sexual assault — unless the judges put on written record their reasons for a lower sentence.

Even then, however, no prison term for such offenses could dip below five years, said state Sen. John Campbell, D-Quechee, and Rep. Michael Kainen, R-Hartford, the two lawmakers who brokered the deal.

Currently, there are no mandatory minimum sentences for sex offenders in Vermont, and prison terms vary widely from case to case. The Montpelier-based Vermont Center for Justice Research found that the median minimum sentence for aggravated sexual assault in 2005 was eight years. Because the range of sentences varies so widely from county to county, however, officials say coming up with a "typical" sentence is difficult.

While the sex offender legislation addresses a number of issues, including an expansion of the state's community notification program, the two chambers' differences on mandatory sentences had threatened to kill the entire bill.

"If you look at the crime bill we just passed, you'll see one of the most comprehensive models" in the country, Campbell said. The plan must now be presented to each chamber. If both the House and Senate approve the compromise, it goes to Gov. Jim Douglas. Douglas would "very likely" sign the measure into law, Douglas spokesman Jason Gibbs said yesterday.

Senate Judiciary Committee Chairman Dick Sears, a Bennington Democrat, had been standing firm on a 10-year mandatory minimum. House members had been pushing for a five-year "advisory" minimum.

State senators in Vermont had been under intense political pressure to adopt mandatory minimums, and 25-year-mandatory minimum sentences are a key component of the so-called "Jessica's Law" proposals — named for a 9-year-old girl who was raped and murdered last year in Florida — that are sweeping the nation.

Kainen said yesterday that the so-called "presumptive" minimum of 10 years in the agreement represents one of the most significant compromises in the Vermont legislation. Judges will not take lightly, he said, the prospect of having to put on the written record their reasons for handing down sentences of less than 10 years.

Critics of mandatory minimums, particularly long ones like the potential 25-year term for first-time offenders called for by New Hampshire Gov. John Lynch, say they hurt prosecutors' ability to strike plea bargains with defendants rather than risk a trial.

It was the decision of a Vermont judge earlier this year that prompted calls for mandatory minimums in the state. Judge Edward Cashman in district court in Burlington this past January originally sentenced admitted child molester Mark Hulett to 60 days of jail time and lifetime probation.

Cashman said then he felt it was essential that Hulett be quickly enrolled in a treatment program; offenders who, like Hulett, had been designated as "low risk" of re-offending could not receive treatment in prison at that time. After the Department of Corrections changed course and started an in-prison program for low-risk offenders, Cashman extended the minimum prison term to three years.