DEMAREST, N.J. — Jason Baretz wore a striped convict’s outfit as he addressed a group at Northern Valley Regional High School at Demarest on a recent Monday evening.

The get-up was a costume, but Jason, 16 and a junior at Northern Valley Regional High School at Old Tappan, the district’s other high school, was not acting in a school play. He was voicing his opposition to random drug testing before a public meeting of the board of education.

“Ladies and gentlemen of the board, I’ve come here today to ask you to look down upon me as a criminal,” he said. “Not because I have engaged in anything unlawful, but because this is how a random drug testing policy will make kids feel.”

Since the spring, the Northern Valley district, which serves seven towns in Bergen County, has been in the grips of a fierce and sometimes personal fight over a proposal to conduct random drug testing on students who participate in extracurricular activities, including sports.

John Schettino, the board president, said he decided to support a testing program in light of evidence of the rising level of drug use, especially the use of opiates and heroin, among high school students in North Jersey.

“Heroin is cheaper than a six-pack of beer now,” Mr. Schettino said in an interview. “Based on my own research and information provided to the school board, I thought it was an effective program when coupled with strong education, counseling and suspicion-based testing.”

Kathy Fable, a board member who supports random testing, said during the meeting that 90 percent of Northern Valley Old Tappan students had tried marijuana and 60 percent had tried opiates or other pharmaceuticals.

But opponents like Jason’s mother, Anne Baretz, say testing creates an atmosphere of distrust and overstepped boundaries.

“We’re talking about the school involving itself in the behavior of students outside the school, which is not their province,” Ms. Baretz said in an interview.

She added that she had found reports that indicated random testing was ineffective at curbing drug use and that board members ignored them.

“How can you have a board of education that wants to operate in ignorance?” she said.

Opponents of testing have accused supporters of exaggerating the extent of the drug problem. By comparison, a 2012 national drug use survey conducted by the University of Michigan’s Institute for Social Research reported that 45 percent of 12th graders had tried marijuana, 12 percent had tried narcotics other than heroin and 1 percent had tried heroin.

Ms. Fable said she got her statistics from Detective Joe Tracy, a police officer who counsels students at Old Tappan. In an interview, Detective Tracy said the numbers were anecdotal and probably inflated. “It’s what students tell me,” he said. “Kids exaggerate.” But he added, “Even if it’s 40 percent, it’s still too high.”

Random testing has grown more prevalent in the United States since the Supreme Courtcondoned it in 2002, ruling that deterring teenage drug use outweighed Fourth Amendment concerns in a public school environment. More than 30 New Jersey school districts have put random testing into effect, though usually without as much public outcry as in Northern Valley.

District officials said that they were still weighing what kind of testing to undertake, but that the tests could cover substances like heroin and marijuana and could be sensitive enough to catch alcohol consumed more than a day before. Students who test positive would be barred from activities but would not be arrested or suspended, and positive tests would not appear on disciplinary records. The district already has suspicion-based drug testing.

In New York State, districts may not test students without parental consent. New York City does not have any random testing programs. Kelly Donnelly, a spokeswoman for the Connecticut Education Department, said that in that state, local districts set testing policy, but that she knew of none that performed random testing.

The Northern Valley school board meeting on Sept. 23 drew more than 70 students and parents. Only a small number publicly supported testing, and more than a dozen spoke against it, to applause and cheers. A proponent of testing, Julie Gleason, said she thought other supporters mostly kept mum because they did not want to be condemned.

“Believe me, it’s not that easy to speak when you have 20 people behind you glaring at you,” she said.

The argument between some board members and the public has turned personal. Ms. Baretz’s husband, Bill Baretz, called Mr. Schettino a “pathological liar” at the meeting and accused him of telling other families that the Baretzes encouraged teenage drug use.

Mr. Schettino denied singling out specific parents, but said in an interview that during board meetings, “we’ve had parents get up and say that this is the time for children to experiment.”

Dennis Doros; his wife, Amy Heller; and their son, Adam, a senior at Old Tappan, all of whom oppose testing, approached the microphones in front of the board clutching printouts of a post Ms. Fable had written on a private Facebook page. In the post, she asked, “Should we be acting on the demands of parents who smoke pot with their kids?”

Adam Doros read the post and said, “This is libel.”

He crumpled up the paper and stomped away from the microphone.

Ms. Fable said in an interview that she thought that taking her broad Facebook statement as an accusation against individual parents was “ridiculous and absurd.”

Conor Wilson, 16 and a junior at Demarest, said that most students opposed testing, but that he was not one of them. He said the threat of being kicked off a team or out of a club could help students fight off peer pressure to use drugs.

“Now I can say, ‘No, I don’t want my number to be pulled,’ ” Conor said. “It’s a stronger stance for kids who want to say no to drugs and alcohol.”

The meeting wore on past midnight. At the end, the board voted to delay considering a proposal until January, when two new board members will be in place, ensuring that the battle would continue for at least several more months.