Six House and Senate lawmakers, after eight months of negotiations, broke through Tuesday evening with a compromise anti-crime and sentencing reform bill that would make certain three-time habitual felons ineligible for parole.

Though the panel negotiating the final bill voted 5-1 to support the compromise, several members of the conference committee expressed reservations about the outcome, including Newton Sen. Cynthia Creem, the chief Senate negotiator who voted against the report.

Rep. Eugene O’Flaherty, the lead House conferee and longtime Judiciary Committee co-chairman, said he would support the compromise, but had his own concerns about eliminating judicial discretion, and questioned the reactionary way laws sometimes are assembled on Beacon Hill.

Though he said the bill would make sure some dangerous repeat criminals serve their full sentences, O’Flaherty told the News Service after the vote, “Anytime that we add more mandatory minimum sentences it concerns me. I think that in Massachusetts we have a judiciary that’s appointed and they’re appointed to exercise their judgment.”

He added, “We shouldn’t be making law based on who screams the loudest or who can tell us the worst story. We should be making law that I think makes sense in terms of what society wants.”

The agreement struck between House and Senate negotiators brings a repeat offender proposal known as “Melissa’s Law” one step closer to completion. House and Senate counsel were reviewing the bill Tuesday evening and aides said it was filed before 8 p.m. so that it might be considered by the full House as early as Wednesday.

Gov. Deval Patrick has said he wants to sign a "balanced bill” that couples sentencing reforms to ease prison overcrowding with a crackdown on habitual offenders. O’Flaherty said this bill strikes a balance and if lawmakers can move the bill to Patrick’s desk, it will be up to the governor to decide if that balance is the one he is looking for.

Les Gosule, whose daughter Melissa was raped and murdered in 1999 by a habitual felon, has been pushing for a strong habitual offender law for years, and the initiative gathered steam this session following the 2010 shooting death of Woburn Police Officer John McGuire by repeat offender Dominic Cinelli.

The habitual offender initiative agreed to by the conference panel covers 46 crimes, and felons would have to be sentenced to at least three years in state prison for one of those crimes to qualify as a strike on their record. After a third strike, or for felons serving two life sentences, parole eligibility would be eliminated.

“I think we at last have a product which is in the best interests of the public safety of the Commonwealth of Massachusetts, and first and foremost a product which responds to the public safety threat which is posed by those who would recidivate with regard to violent felonies,” Senate Minority Leader and conferee Bruce Tarr said.

Creem expressed her opposition to House negotiators’ decision to resist inserting a “safety valve” into the bill that would have given judges the discretion to grant parole to three-felons.

Explaining her concerns with the compromise, Creem said she has always had reservations about the way the Senate bill dealt with mandatory minimum sentencing for drug offenders, and was “totally confused” why the House “at the last minute” removed the judicial discretion clause from its final offer.

Creem said it was necessary given how the Legislature was poised to increase the number of crimes carrying a punishment of life without parole from one to 20. An amendment to reinsert the “safety valve” provision into the conference report failed 2-4, with Tarr joining Creem in support.

O’Flaherty said the “safety valve” clause “could have created the argument that it was gutting the bill.” Asked then if he was responding to public perception, the Chelsea Democrat said, “Perception is often times the reality, and if the only story on this bill was that, oh, by the way, there’s a safety valve built into it, I think the cynics would point that out and ask, ‘What in essence did the bill accomplish?’”

Instead of Gov. Deval Patrick’s proposal to make drug offenders eligible for parole after serving two-thirds of their sentence, the conference committee opted for the Senate’s sentencing reform plan that would increase the drug weights associated with certain crimes, and reduce the mandatory sentences those crimes carry.

O’Flaherty said the changes, if adopted, could make some inmates who have already served the revised sentence lengths eligible for release from prison immediately.

The conference bill would also reduce the size of school zones that carry increased penalties for drug offenses to 300 feet from 1,000 feet, and would nullify special school zone penalties for infractions between midnight to 5 a.m.

The bill would allow police to take DNA cheek swabs, instead of blood samples, from convicted felons to reduce the backlog of samples, and individuals would be protected from prosecution under a “good Samaritan law” for calling 911 in overdose emergencies.

Also, drug offenders would be allowed to earn good time credits while serving their sentences for participation in occupational and service programs available to other inmates, and prisoners serving a life sentence would need two-thirds support from the Parole Board to be released early under supervision.

Officials did not have estimates on how much the bill could cost the prison system, or how many habitual offenders might be affected by its provisions, though O’Flaherty said the number incarcerated would be “extremely low” and negated by those serving less time on drug crimes.

Critics of the habitual offender measure say its sweep is too broad and its passage will worsen prison overcrowding.

“It is profoundly disappointing that the conference committee is reporting out a bill that is not based on data about the drivers of crime or the cost the bill will create,” said Leslie Walker, the executive director of Prisoners’ Legal Services.

Walker estimated, based on data from the Massachusetts Sentencing Commission, that the state prison population could increase by as many as 300 individuals a year, and cost over $100 million in the next 10 to 15 years.

Walker also criticized the lack of the “safety valve” language: “It would have looked like a thoughtful bill that allows judges to do their job,” she said in response to O’Flaherty’s concerns about perception.

Rep. David Linsky (D-Natick) said the compromise did an “excellent job” at narrowing the list of crimes from the original Senate bill that would trigger habitual-offender status, but said, “We really haven’t addressed the issue of parole.”

Linksy said he intended to push next session for a second look at mandatory minimum sentencing laws for drug offenders, and said they should be eligible for parole.

O’Flaherty also said he expected the House to revisit mandatory minimum sentencing next year, and Rep. Brad Hill, an Ipswich Republican, said he would stand in bipartisan fashion to get something accomplished.

“It has been my goal for over ten years, through the original filing of Melissa’s Bill and zealous advocacy, to pass legislation that ensures the most heinous and violent criminals remain behind bars in order to protect the citizens of the Commonwealth,” Hill said.

Sen. Jennifer Flanagan (D-Leominster) applauded the inclusion of the “Good Samaritan” protections.