The husky drug-sniffing dog careens between a row of middle-school lockers, nose held high. Posters dot the walls above him, displaying the flowery lettering of adolescent scribes.
Suddenly the dog halts, alerted by a passing scent. But it's just a false alarm, and soon he's on the move again, his US Customs Service handler shouting encouragement and racing to keep up.
The setting is Sierra Vista, a growing community along the Arizona-Mexico border, a 90-minute drive from Tucson. Law-enforcers and their drug-sniffing canines roaming the hallways here symbolize just how seriously the drug problem is being taken in America's schools.
From locker searches to random urine testing for students who participate in extracurricular activities, schools have stepped up the antidrug effort since being granted wider latitude by a Supreme Court ruling last October.
And now, for the first time, school districts like Sierra Vista are teaming up with the US Customs Service and its drug-detecting resources.
The program, in which dogs are periodically brought in for locker searches, aims to train the Customs dogs in a wider array of settings as well as help keep schools drug free. But controversy over the program encapsulates the debate over which drug-prevention tactics are effective and appropriate in schools.
The consent is virtually unanimous that drug abuse among teenagers is a serious problem. According to a study by the National Center on Addiction and Substance Abuse, the number of high school students who said drugs were widespread in their schools rose from 72 percent in 1996 to 78 percent last year. But many parents object to their children - or their lockers - being searched unless the school has reason to suspect them.
Federal funding for drug prevention among youths has also been growing, and now tops $20 million annually. Much of that money is funneled through the US Department of Education's Safe and Drug-Free Schools and Communities Program, paying for efforts such as the popular Project D.A.R.E. (Drug Abuse Resistance Education) and on-campus drug-prevention coordinators.
The money is also used for massive media campaigns that, like dog searches, aim to scare students into staying straight.
Emphasizing the stick over the carrot is a mistake, according to some researchers.
"When a school elects to bring in the police or that kind of thing, it gives a very negative message to the students," says Kris Bosworth, a scholastic drug-prevention expert at the University of Arizona in Tucson. "It says that we don't trust them, and that there's something going on that's wrong."
The key is allowing students a voice in how their schools tackle the problem. This gives them a greater sense of power, enhancing what Ms. Bosworth calls "school culture" - the overall physical and psychological atmosphere on campus.
"Culture is the most pervasive influence in a school, and should be the top priority" for prevention efforts. "Yet it is often the least ... addressed."
Indeed, many districts are going in exactly the opposite direction. Get-tough tactics like dog searches and weekly drug testing may not only strain the student-school relationship, but test legal boundaries as well.
"We're very, very concerned about it, especially under the circumstances where there is no individualized suspicion," says Eleanor Eisenberg, executive director of the Arizona Civil Liberties Union.
Regardless of whether such searches are legal in the strictest sense, when Customs officials enter schools, "they still maintain the character of law enforcement," Ms. Eisenberg says. "It's very frightening. One wonders about the learning environment that's created."
To Gary Garrison, such worries are misplaced. As substance abuse prevention coordinator for the Sierra Vista School District, he spearheaded the dog-search program and isn't deterred by its critics.
He says students were introduced to the dogs during fall presentations, and he's careful to maintain their rights. "We never search a student one-on-one with the dogs. Most of the time, we do the locker areas and the school property. Then, if the dog hits on something that belongs to a student, we immediately leave that area with the dogs and turn it over to administrators."
Mr. Garrison considers the searches "a good deterrent" to those who might bring drugs on campus, and reports widespread support from students and their parents:
"One student did tell me, 'I know it's a bad state of affairs that you have to bring dogs into the schools.' Then on the same note, he said, 'I understand, because we have shootings in other parts of the country. So it's not that I'm upset,' he told me. 'It's the times we live in that bother me.' "
Proponents of canine searches also point to studies that have shown D.A.R.E. - the most widely used school antidrug program in the US - to have little long-term impact on children's drug use. Prevention may someday be effective, they say, but deterrents are key in the interim.