When you’re a teenager influenced by a hubris culture, taking a picture of yourself (a “selfie” as they say) and your friend wearing ski masks and clenching knives is the only way to show how cool you are, even if it’s used against you in a court of law.

Such is the case with a 17-year-old girl and her accomplice. According to reports in the Swedish edition of news website The Local, before they robbed a Max hamburger restaurant in Halmstad, southern Sweden in March of this year, they took pictures of themselves with their smart phone. In one of the pictures, the two girls wear hoodies and balaclavas; one girl holds her phone with one hand – in the other, she clenches and holds up a 30cm (11.8 inches) kitchen knife.

According to The Local, the two girls wound up stealing 2,420 krona ($368) from the diner. A court heard witnesses say that the girl held up the restaurant staff, brandishing the knife and yelling: “Give me the money, or I’ll stab you!”

Around 47 minutes after the crime, police with sniffer dogs tracked down the two girls. The first piece of evidence they police uncovered was a bag filled with money, the second was the phone that contained the incriminating photos. Police were able to trace the dastardly duo back at one of the girls’ grandmother’s home.

Last Friday, the eldest girl who was found at the grandma’s house was convicted and sent to juvenile detention. During the mitigation, the court uncovered that the girl had a difficult childhood and had been thrown out from her family home. Her sentence would have been harsher had she been 18; the girl will receive treatment from a youth psychiatrist.

The other girl, despite overwhelming evidence, was not convicted due to a lack thereof. She had told police that the pictures taken in the mirror were nothing more than a mere joke.

The Local also reported that among the evidence was the phone that contained numerous selfies, a picture of the money, and a quote by US poet Ralph Waldo Emerson, which read: “Commit a crime and the world is made of glass”.

(Picture via Swedish Police)