The neighbors were the first ones to complain to the cops about the party. By the time officer Sean Magill drove up to the house, kids were jumping from the windows.

Scenes like that aren’t common in St. Helena, but the underlying problem of teen drinking is all too familiar. Members of the St. Helena Partnership on Youth Substance Abuse met with local law enforcement officials to discuss law enforcement strategies relating to the potent mix of kids, alcohol and partying.

The Partnership is a division of the county-wide Catalyst Coalition, fighting underage drinking and drug abuse throughout Napa County.

Magill and Chief Monty Castillo from the St. Helena Police Department explained the city’s approach, while the Napa County Sheriff’s Department’s Chris Perry and Jon Thompson provided a county perspective.

Law enforcement uses several laws to fight youth alcoholism. The most basic law prohibits people under 21 from possessing alcohol in public. According to St. Helena Police Department policy, the decision of whether or not to cite lies in the hands of the officer. Contrary to what some believe, the police do not choose whether to cite kids based on their parents’ social status, Perry said.

Enforcing this law is not as easy as it seems. If the kids ditch the alcohol before officers arrive or have already consumed the alcohol, the law doesn’t apply. If a kid who’s been drinking hands their drink to a friend before the officer can see it, that friend can be cited, whether they’ve drunk anything or not.

In the past, police have used the law to arrest kids who didn’t possess alcohol, but had clearly been drinking. However, the Napa County district attorney’s office told police that those cases can’t be effectively prosecuted.

Teen drinking can get particularly out of hand at parties. In the wake of the wild birthday party described by Magill — 15 guests turned into 100 — five officers from the city and county were needed to sort things out: writing down everybody’s name and contacting all the parents whose kids had been drinking.

During another party, one juvenile got belligerent and combative with St. Helena cops, Magill said. It took three officers to subdue him, and all three of them were injured during the struggle. Two of them were out for weeks, and one was hurt so seriously that he retired a year and a half later.

In labor-intensive cases like that, the police have the right not only to charge whoever threw the party, but to recover law enforcement costs from parents. In addition to wages, the police can recover costs associated with the officers’ health and benefit packages and the use of the police car and related equipment.

Perry said that although the Napa County Sheriff’s Department frequently investigates teen parties, particularly in American Canyon, the agency rarely seeks to recover its costs. That step is usually reserved for repeat offenders, he said.

Sometimes a party is shut down as law enforcement arrives, only to resume there or at another location when the police have gone. Manpower is a primary concern in chasing down such parties, officers agreed.

Understaffing has forced the St. Helena Police Department to have just two officers on duty at most times, but Castillo hopes soon to increase that number to three.

The force’s newest cop, Kenny Trimble, will be finished with his field training in the next few days. Another cop could join the department later this month, and Castillo is conducting a background check on another potential officer. With those spots filled, only the supervising position vacated by the retired Sgt. Wayne Martin will remain.

It’s widely known that it’s a misdemeanor for anyone to drive with a blood alcohol content (BAC) over .08 percent. But the law is much stricter for people under 21 — minors who get caught driving while having any amount of alcohol in their system lose their license for a year. And whereas the sobriety tests undergone by suspected drunk driving adults are voluntary, licensed people under 21 are required to pass the test.

Cops can also charge people of any age with a misdemeanor if they provide alcohol to minors. A more specific law says that parents or legal guardians can be guilty of a misdemeanor if they knowingly permit their kids or their kids’ friends to drink or use drugs at home, and the kids then get into a car accident.

A public intoxication law prohibits anyone from being in public when they are so intoxicated that a police officer judges them unable to care for their safety or the safety of others. This law is useful when someone might not possess alcohol, but clearly has been drinking and is a danger to themself or others.

However, county cops face a significant obstacle in enforcing this law. Adult drunks can be carted off to the county jail, but the authorities at Napa’s juvenile hall don’t accept intoxicated juveniles without the time-consuming process of getting medical clearance from a local hospital.

“It’s clearly a misdemeanor offense,” said Chief Probation Officer Mary Butler Tuesday. “But it’s generally not something that we would want to keep a young person in juvenile hall for.”

Perry said that if a minor is drunk and county cops can’t find their parents, they have to drive them around in the back of their police car, sometimes for the better part of a day.

Perry said the problem comes up often, particularly at Lake Berryessa in the summer. He said it would be a great help if juvenile hall regularly admitted intoxicated kids.

St. Helena cops also struggle with this law. Minors arrested for public intoxication by St. Helena police can’t be placed in the department’s single holding cell unless they are combative or have committed a felony, so they usually end up sitting at the department with an officer or a dispatcher if cops can’t round up their parents.

Kids who are drunk at school or a school function can be eliminated from athletic activities. The same consequences apply to kids who are cited for public intoxication by the police while away from school.

However, if the minor has been drinking but does not possess any alcohol, and is not at the public intoxication level — if the officer doesn’t consider him or her a danger to themself or others — police can only take them into protective custody, not cite them.

But in spite of the law enforcement battle against teen drinking, officers agreed that parents are the first and best line of defense.

Magill encouraged parents to “be snoopy.” Parents can search their kids’ belongings and continually interrogate their kids on where they are at all times, with frequent follow-up calls to other parents to make sure the stories check out.

Castillo added that responsible mentors can also have a tremendous effect on the decisions kids make, particularly if the kids don’t have a responsible parent.