These proposals reflect recommendations issued in March by a task force led by state Supreme Court Chief Justice Stuart Rabner.
"There's a 50-50 chance" that the amendment is put before voters in November, Senate President Stephen Sweeney (D., Gloucester) said in an interview this week.
"I would love to be able to get this done this year, if we can get it right," he said. "We're close. We're not there yet."
Legislators have been meeting with various organizations, activists, and court officials for months to hammer out the details.
Supporters of the proposals say they want to ensure that those who pose a danger to others stay behind bars. They also want to keep nonviolent defendants who can't afford bail out of jail.
Defendants would not automatically be detained without bail. Prosecutors would have to file a motion requesting detention, and a judge would hold a hearing.
A person familiar with the Christie administration's thinking said the governor viewed the Legislature's bail proposal as too weak. That version would limit revocation of the right to bail to those who commit first-degree crimes - which wouldn't account for all potentially violent individuals, the source said.
Assemblyman John Burzichelli (D., Gloucester), a bill sponsor, said his primary interest was "to get people out of jail that aren't a threat to society . . . so they don't make bad plea-bargain deals."
Replacing the bail-based system would be a statewide risk-assessment program that would consider objective criteria in evaluating a defendant's risk of flight and potential danger to the community. The program would be used to make recommendations to the courts concerning pretrial release.
Bail still could be used as a condition for release in certain circumstances.
The legislative push comes about a year after Rabner established the Joint Committee on Criminal Justice to review issues of bail and trial delays.
"Among other important precepts, our criminal justice system stands on two bedrock principles: that individuals accused of a crime are innocent until proven guilty, and that they are entitled to a speedy trial," the committee said in its March report.
"Yet many defendants are detained in jail before and during trial - while they are presumed innocent - because they cannot post bail. And all too often defendants have to wait far more than a year to see their day in court."
An average of 9,000 defendants are held while awaiting trial on any given day in New Jersey, according to the report. They generally remain incarcerated pretrial for 60 to 90 days, at a cost of $100 a day each.
The report also pointed to a variety of apparent inequities: A recent study found that 12 percent of the state's county jail population "remained in custody because they could not post a bail of $2,500 or less." More than two-thirds of those defendants were minorities.
Those who remain incarcerated before trial face worse outcomes than those who are released, such as pleading guilty more often and receiving harsher punishment, the report said.
Most legislators and interested parties agree that changes are needed in the criminal justice system. But there isn't universal agreement on which ones.
Much of the debate has focused on what language should be included in the constitutional amendment, Burzichelli said.
There is disagreement over what level of offense could warrant pretrial detention without the option of bail.
Burzichelli's bill, which advanced out of committee in June, would make those who are charged with the most serious violent crimes eligible for such detention.
"Others would like more discretion as to who can be held, who can't be held," Burzichelli said.
Gov. Christie also has called for a constitutional amendment modifying the right to bail afforded to "all persons."
Christie "sees bail reform as an important priority for the state to finally get done," spokesman Kevin Roberts said Tuesday. "We feel like we're closer than we've ever been on this. It remains a priority for us because it's an important issue of public safety."
If changes to bail are included in the constitution, some legislators also want a provision that would establish speedy-trial deadlines. Currently, the constitution gives all persons the right to a speedy trial, but doesn't define what that means.
Lawmakers also are considering including the speedy-trial provision in accompanying legislation.
Under Burzichelli's bill, defendants ordered to pretrial detention without bail could not be detained for more than nine months before trial.
But the speedy-trial provision wouldn't apply to defendants released from jail before trial. State Sen. Nia Gill (D., Essex) said the difference in treatment raised constitutional concerns with regard to equal protection under the law.
To make the ballot, a constitutional amendment would have to pass both houses of the Legislature three months before the Nov. 4 general election. For other procedural reasons, the proposed amendment must pass a committee of one house by Monday.
While the amendment doesn't need Christie's support, he can veto the accompanying legislation. For that reason, Burzichelli has said that the Legislature would move forward with the amendment only if it could come to an accord with the governor.