EDITOR’S NOTE: Entrepreneurs everywhere are eyeing the billion-dollar legal weed industry, an economic opportunity unrivaled in modern N.J. history. NJ Cannabis Insider features exclusive weekly content geared toward those interested in the marijuana industry. View a sample issue.

As New Jersey lawmakers wrestle over whether to legalize marijuana, about half of the state’s local police departments lack officers who are specially trained to detect drivers under the influence of the drug, according to the state’s top law enforcement official.

State Attorney General Gurbir Grewal told a state Assembly budget panel in Trenton on Wednesday that his department, which includes the State Police, continues to train officers as “drug recognition experts,” also known as DREs.

“We have been anticipating the Legislature and the governor acting on some form of legalization for some period of time, so we have been ramping up our efforts to increase the number of DREs,” Grewal said.

Currently, the state has about 520 law enforcement officials trained as DREs, up from about 400 this time last year. Grewal told the committee his office is aiming to train 100 new DREs each year.

Gov. Phil Murphy, a Democrat, made legalization a major part of his campaign, but an effort to push a vote through the Democratic-controlled state Legislature last month fell apart at the last minute. Leaders in the Legislature remain confident a recreational marijuana bill will pass, but they have yet to convince enough of their colleagues to approve such a measure.

Legal experts and law enforcement officials told NJ Advance Media earlier this year that legalization would likely lead to an increase in legal challenges to how cops on the road measure cannabis intoxication, citing court cases here in New Jersey and around the country.

Currently, just over 200 of New Jersey’s more than 400 local police departments have their own drug recognition experts, the attorney general said. He added that the State Police, which makes its experts available to departments that don’t have their own, is looking to train all of its 1,400 road troopers in drug recognition.

“From our perspective, we’ll be ready,” Grewal said of ongoing negotiations in Trenton over legalizing recreational marijuana. “We’re increasing training, trying to offer more classes. But it’s an intensive program.”

The program includes about two weeks of course work and a week of field training, he said.

State authorities have also changed how they train drug-sniffing dogs in anticipation of legal weed. The attorney general noted that state K9 units have stopped “imprinting” marijuana smell detection on new police dogs because of constitutional issues that would arise from an animal that can’t distinguish from legal and illegal drugs.

“Once a dog is imprinted with marijuana, you can’t un-train that dog,” Grewal said, noting that if legalization occurs, the current crop of K9s could still be used in places where marijuana is not permitted, such as schools and prisons, but could not be used to determine probable cause for a search on the road.

Meanwhile, a key lawmaker, state Sen. Nicholas Scutari, D-Union, said at a separate event hosted by NJ Cannabis Insider on Wednesday that he is hopeful a new legal weed vote could come as early as May.

S.P. Sullivan may be reached at ssullivan@njadvancemedia.com. Follow him on Twitter.

Have a tip? Tell us. nj.com/tips

Get the latest updates right in your inbox. Subscribe to NJ.com’s newsletters.