Starting Sunday, family members and authorities in New Jersey will be able to use a new law to seek a court order to strip firearms from those considered dangerous — legislation decried by gun rights groups as an end run around the Constitution.

Even as New Jersey joins the growing list of states with a so-called red-flag law, questions remain about whether it will help prevent gun violence.

While some studies found that suicide rates dropped in states with red-flag laws, determining whether they can reduce homicides — and mass shootings in particular — is harder to do, experts said.

“Mass shootings are a rare event,” said Warren Eller, associate professor and chairman of the Department of Public Management at the John Jay College of Criminal Justice in Manhattan. “Because that’s the case, it makes it incredibly difficult to say what’s actually going to have an effect, and even to test what that effect would be with any certainty.”

Despite this, 17 states and the District of Columbia now allow for some version of the law, which in New Jersey will let judges issue an “extreme risk protection order” that gives authorities the green light to take an individual’s weapons.

The public overwhelmingly supports the measures, according to a July survey by the American Public Media Research Lab. More than three-quarters of those polled favor allowing families to seek an order, and about 70 percent support allowing police the option.

But it is not without detractors.

The National Rifle Association often decries the laws as confiscation schemes that violate the right to due process. Yet the survey found that most gun owners support them — 60 percent back police-initiated orders, and 67 percent support family-initiated orders.

It remains unclear whether a federal red-flag law will gain traction. Though the survey showed bipartisan support from the public, politicians in Washington have been unable to come to terms.

Last year, courts across the nation issued more than 1,700 orders under red-flag laws allowing authorities to seize weapons for up to a year. The actual figure may be higher, as California was not included in the data.

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The New Jersey law

In a statement earlier this month, state Attorney General Gurbir Grewal commended the law, which goes into effect Sept. 1.

"New Jersey is leading the way in taking commonsense action to protect our residents and law enforcement officers from the daily scourge of gun violence," Grewal said.

Previously, police could not file their own petition, Grewal’s office said. And families could do it only after an act of domestic violence.

That's not the case under the new law: Family, household members or cops can now request an order before a crime occurs.

However, the petition must show that the respondent "poses an immediate and present danger of bodily injury to self or others by possessing, purchasing, owning or receiving a firearm," according to an attorney general directive. The judge will then consider the respondent's legal history, arrest record and previous convictions, among other things.

Once the order is granted, the judge can issue a search warrant that lets authorities seize the respondent's firearms and ammunition, as well as the person's firearms purchaser identification card, permit to purchase a handgun and permit to carry a handgun, if there is one.

The state Superior Court then schedules a final hearing within 10 days, at which point a judge can permanently bar the respondent from owning, handling or buying firearms, according to the law. That order lasts until a judge cancels it, which would follow another hearing in which the respondent must prove not to be a threat.

Authorities can charge those who break any provision with a fourth-degree crime.

The directive also details an appeal process and lays out how and when officers and prosecutors should file for an order.

Despite the high legal bar, gun rights groups are crying foul.

“This is classic Orwell — people are charged and convicted of something based on nothing more than an accusation,” said Alexander Roubian, president of the New Jersey Second Amendment Society. "You don't have the right and the ability to defend yourself ... before your firearms are taken away from you."

An NRA spokesman echoed this, writing in an email that red-flag laws should, at a minimum, include criminal penalties for those who make frivolous claims, require mental health treatment for respondents and protect their right to due process.

The New Jersey law does not require treatment or explicitly mention penalties, a spokesman for the attorney general said. But the petitioner's affidavit will be sworn under oath, making the petitioner subject to punishment if statements are willfully false, according to a court directive.

Due process is a concern, said Michael K. Gusmano, an associate professor and outreach director for the Gun Violence Research Center at Rutgers University. That's why it's important that the state train police, prosecutors and the courts appropriately.

"You're talking about having the state come in and remove, in most instances, a legally purchased gun," Gusmano said. "But the claim that these laws do not involve due process because the person has not already been convicted of a crime does not make any sense ... the whole premise behind these are that you're trying to be preemptive."

Others worry about false accusations, which could strip weapons from innocent people.

"It does happen," said Paramus Police Chief Ken Ehrenberg. "We must make sure that the seizures are for a legitimate reason and the law doesn't get abused."

Still, he said, the law will give his officers another way to keep firearms out of the wrong hands.

Bergen County Sheriff Anthony Cureton, a Democrat in his first term, added that he thinks the law is "more than appropriate."

"If someone has a gun in their household and they're not stable, we need the opportunity to take the gun out of somebody's hand," Cureton said. "It's about safety first."

Email: janoski@northjersey.com