Against a backdrop of growing concern over use of alcohol and drugs by Vineyard teens, police will seek criminal charges against a West Tisbury couple who allegedly allowed underaged drinking to take place on their property during a teenage party last weekend off Lambert's Cove Road.

By the time police arrived late last Saturday night, the party had attracted some 70 kids and more than 40 cars.

Police arrested two teens and plan to summons two more on charges of possession of marijuana, alcohol or both. They placed a fifth teenager, a 17-year-old, into protective custody because he was too intoxicated to drive and vomited while talking to police officers who were called to the scene after a neighbor complained about noise.

If the charges against the two adults, Klaus and Vicki Broscheit of Seth's Lane, are approved Nov. 12 at a show-cause hearing in Edgartown district court, it would mark the first time that Cape and Islands prosecutors will try to hold parents responsible under an amendment to state law that makes it illegal to knowingly allow a person under 21 to consume alcohol on property they own.

Assistant Cape and Islands district attorney Lisa Edmonds told the Gazette yesterday that prosecutors in her office have not pursued any cases under the law since it was amended two years ago.

If the Broscheits were to be convicted of violating the statute, they could face a jail term of one year and fines of up to $2,000 each. Mrs. Broscheit yesterday denied any knowledge that teenagers were drinking alcohol on their property last Saturday.

"My youngest son wanted to have a party, and he invited 20 friends," she said. "Everything was fine when my husband and I went to sleep around 10. But soon after 10:30, kids just started crashing the party, and some brought alcohol."

But documents in Edgartown district court show that police had warned the Broscheits last year about allowing unsupervised parties at their home at which minors were drinking.

According to a West Tisbury police report from last October, police investigated the alcohol poisoning of a 15-year-old girl and learned that she had consumed vodka - as much as 15 shots - at a party in the Broscheits' garage apartment.

When the girl arrived home, she passed out and was taken by ambulance to the Martha's Vineyard Hospital where her blood-alcohol reading registered 0.25, more than three times the legal limit for an adult who gets behind the wheel of a car.

"Both parents advised that they allow their son to have friends over to provide them with a safe environment," the 2001 police report stated.

"After speaking with Mr. and Mrs. Broscheit, it was determined that they were not aware of any alcohol being present, and that any further gatherings would be strictly supervised," that report continued.

Last Saturday night, police found plenty of evidence of alcohol. When West Tisbury police Cpl. Matthew Mincone arrived, he saw a car backing down the driveway with a bottle of vodka sitting on the car roof. When they stopped the car and handcuffed the driver and passengers, they searched the car and discovered a bottle of rum and two pipes with marijuana residue.

According to the official report, police saw in another car a bottle of Carlo Rossi wine; officers later found the car's driver, a 17-year-old who will be charged with possession of alcohol.

"As I left the residence, I walked by a dumpster and observed several beer boxes and cans," Corporal Mincone wrote in his report.

Among the teenagers arrested Saturday night was the Broscheits' son, Klaus Broscheit Jr., a 19-year-old student at the University of Massachusetts Amherst. He was charged with disturbing the peace and providing a place for minors to consume alcohol.

In the wake of the arrests and eyeing the possibility of more charges, police and even school officials are now saying that the problem of teen drug and alcohol use is only getting worse.

"When I hear about a party like this with that many kids, and it appears allegedly to be condoned by the family, I'm very upset," said West Tisbury police chief Beth Toomey. "We keep saying, what are we going to do about the kids, but this education is for the adults."

"We're at the upper end of the cycle," said Chilmark police chief Tim Rich of the problem of teen drug and alcohol use. "What's of more concern to me is the availability of alcohol. It seems that the alcohol is flowing freely."

Police say they've clamped down on the liquor stores and now suspect that teens are using fake IDs or tapping older friends who may have graduated from high school but stayed on the Island.

High school principal Peg Regan told the Gazette that school staff members are hearing that "alcohol and marijuana use are pretty liberal and rampant now."

Amy Lilavois, a counselor at Martha's Vineyard Community Services who specializes in working with adolescents, believes that use of cocaine and ecstasy are both on the rise among Island teens.

Statistics gleaned from surveys of Island teens bolster the concerns of school officials, police and counselors. The last two surveys of risky behavior have shown Island teens engaging in drug and alcohol use at rates that exceed those of their peers statewide.

Nearly 60 per cent of Vineyard high school students who took the survey last winter reported drinking alcohol in the previous month. The latest statewide results, released just this week, show that 50 per cent of high school students surveyed statewide reported current alcohol use.

The comparisons are even more staggering for marijuana, which seems to have a strong foothold on the Island. Statewide, just 26 per cent of high school students responded that they had smoked pot in the previous month. On the Vineyard, that figure is 44 per cent.

What's more, both police and counselors who work with the Island's youth are convinced that the results are underreported.

"Everything is higher than what we're reading," Chief Toomey told the Gazette last summer.

Faced with such numbers, school officials and counselors have tried to battle the issue by sponsoring forums and substance-free events. They haven't given up hope of making a dent in the problem.

In December, a social worker from Maine named Steven Andrew will return to the Island to work with students, school staff and the public on ways to steer teens into positive activities and away from the weekend party scene.

"If we're all encouraging kids to be the best they can be, it's one giant antidote to self-destructive behavior," said Mrs. Regan.