Early in the morning of April 18th of this year, plain-clothes police officers fanned out across the city to knock on the doors of the homes of several students from the Åsö school, a grade 7-9 middle school located on Södermalm.
The startled students were taken down to the police station and interrogated about suspicions they had been using and selling marijuana on school grounds.
"They pulled me out of bed while I was still sleeping," one 16-year-old student told the Aftonbladet newspaper at the time.
But despite the large-scale operation, police failed to find any drugs or yield enough evidence to file any formal charges against the 14- to 16-year-old students.
Nor did any of the students questioned in the raid test positive for having used cannabis.
"A couple admitted to having smoked and two of them to having sold it, but since neither of them tested positive, their testimonies were not enough to prosecute them,” Patrick Widell of the youth crimes division at the Stockholm County Police and head of the investigation, told The Local.
"The case in now closed."
Widell explained that prior to the raid, officials and teachers from Åsö school had informed police about suspicions that two adults were selling cannabis to students at the school, and that several of the students were smoking the drug.
Police also learned from the school that several of the students had tested positive for marijuana after being taken by their parents to Maria Ungdom, a Stockholm clinic that deals with substance abuse issues among young people.
Following the tip, the police carried out the raid in coordination with the school and social services.
The raid generated a flurry of media coverage across Sweden, with some outlets reporting that as many as forty students had been taken in by the police and subjected to drug tests for possession of marijuana.
However, much of the reporting turned out to be exaggerated.
According to Widell, around ten students were questioned as a part of the initial operation, with a few more being brought in for questioning afterward.
Ultimately, four people – two of whom were adults – were suspected for selling drugs.
“The students who were brought in at first were not suspected for smoking marijuana. But when we spoke to them and investigated their text messages on their mobile phones it was confirmed that they had [smoked cannabis],” said Widell.
According to a July 2012 report from the Swedish Council for Information on Alcohol and Other Drugs (CAN), marijuana was the most commonly used drug among ninth graders in Sweden in 2011.
The CAN statistics reveal that around six percent of Swedish ninth graders smoked marijuana last year, an increase of one percent since 2000.
However, the percentage of teenagers in Sweden who say they have at some point used drugs has decreased by about half 1971, according to CAN’s statistics.
Considering that drug use among Sweden's young people on the decline and that none of the students singled out in the Åsö school raid tested positive for marijuana, some have questioned the police's methods in the crackdown.
"It doesn’t sound like the police have been very effective in this case,” Karin Svanberg, section head at Sweden's National Council on Crime Prevention (Brottsförebyggande rådet – Brå) told The Local of the raid.
"The best way to deal with this problem is to give kids proper schooling and fill their free time with constructive activities."
She added, however, that while drug raids at schools aren't that common in Sweden, police certainly should "take action" to combat suspected drug use.
But Svanberg was hesitant to categorize the raid as a "preventive action", which is exactly how Widell of the police referred to it in justifying the action despite the fact that none of the students singled out in the raid tested positive for cannabis use.
“This action should be viewed as an effort to prevent the students from committing crimes when they’re older and, seen this way, our action was successful,” Widell said.
Despite concerns that school officials may have violated students' privacy in connection with the operation, the Child and School Student Representative (Barn- och elevombudet, BEO) at the Swedish Schools Inspectorate (Skolinspektionen) said both police and the school acted appropriately.
“If the police suspect that students have committed a crime, they may do whatever they like according to governing legislation," BEO spokesperson Carina Larsson told The Local.
"The students may have felt that the police may have violated their privacy, but we haven’t received any complaints from the students.”
Widell of the police also had a theory as to why none of the students tested positive for marijuana.
"Kids at this age don’t inhale the smoke properly. That’s one explanation why they didn’t test positive,” he said.
Widell also explained that any of the students that tested positive at Maria Ungdom may have become scared and stopped using marijuana or been more careful and thus passed the drug tests administered by police in connection with the raid.
Stefen Sparring, a specialist and section head at Maria Ungdom, emphasized that at no point did the clinic give police any information about visits by students.
“We never cooperated with the police or gave them any type of information about who they should bring in,” Sparring told The Local.
He also disputed Widell's theory about that kids don't know how to smoke marijuana properly.
“If you smoke you smoke to get high and then you inhale,” said Sparring.
According to Sparring, the raid must be seen in the context of what he described as Sweden's "no-tolerance" approach to marijuana use.
“We could discuss if the police’s methods were appropriate, but considering the stated intentions, I think the raid was a good way to show the kids that selling or using drugs is not acceptable,” he said.
“If you compare us to England, where they go about things differently and don’t do anything in order to protect people's privacy, we could be seen as barbarians."
Sparring argued that, compared to Sweden and many other countries in the EU, England has a high number of drug users, adding that he supports Sweden's hard line approach.
"The police’s raid should be seen as sending a clear message out to young people that smoking and selling drugs is a crime," he said.