When police arrived at this Düsseldorf apartment, they thought that they were dealing with a standard break-in. However, they were about to unravel a mystery that had puzzled authorities for 31 years.

It’s a September day in the German city of Düsseldorf, and police are arriving at the scene of a break-in. They begin quizzing the woman who lives there, and everything seems normal at first. However, when they ask to see some identification, things take a turn for the bizarre. Is the truth behind a 31-year-old mystery about to be revealed?

Back in July 1984 24-year-old Petra Pazsitka was studying computer science at university in Braunschweig, a city in the Lower Saxony region of Germany. With the holidays approaching, she planned to spend her time completing her thesis at her parents’ house in Wolfsburg, some 23 miles away.

On July 26 Petra was preparing for her visit home. She had asked a neighbor to take care of her plants while she was gone, giving no indication that anything was wrong. She then attended an appointment at her dentist, after which she apparently planned to catch a bus to Wolfsburg.

Images: YouTube/Aktenzeichen Laibachs Hoden-Wohl

However, Petra never arrived at her parents’ home. Indeed, two days later, having missed her brother Carsten’s birthday party, she was still nowhere to be seen. Concerned, Carsten subsequently reported her missing, and the search for the student began.

Images: YouTube/Aktenzeichen Laibachs Hoden-Wohl

By January 1985 police had still failed to turn up any sign of the young woman now dubbed “Petra P.” Stumped, investigators turned to the popular German television show Aktenzeichen XY for assistance. First aired in 1967, the interactive program had an impressive reputation for solving crimes.

Images: YouTube/Aktenzeichen Laibachs Hoden-Wohl

As part of the show an actress played Petra in a re-enactment of her last known movements. True to life, the footage depicted a past visit by the student to her parents’ home in Wolfsburg during which she told them about her plans to finish her thesis.

Images: YouTube/Aktenzeichen Laibachs Hoden-Wohl

After that, the re-enactment focused on Petra’s life in her student accommodation, showing her talking to a neighbor about her plants. Then she could be seen visiting the dentist and buying her brother a gift, after which the trail went cold.

Images: YouTube/Aktenzeichen Laibachs Hoden-Wohl

Yet despite this detailed re-enactment, the efforts of the investigators were in vain. Sadly, the episode of Aktenzeichen XY yielded no useful clues, and police were no closer to finding out what had become of Petra. Hence, although they had not discovered her body, they began to suspect that the student had been murdered.

In 1985 the investigation consequently changed from a hunt for a missing person to a search for a killer. Finally, there was a break in the case. Two years previously, a 14-year-old girl had been assaulted and murdered in Wolfsburg – close to the very same bus stop that Petra would have used.

Images: YouTube/Aktenzeichen Laibachs Hoden-Wohl

Then in 1985 a 19-year-old known only as Günter K., a carpenter’s apprentice, was arrested in connection with the teenager’s murder. Furthermore, two years after confessing to that crime, he made another startling revelation: he also claimed to have killed Petra back in 1984.

Nonetheless, despite Günter’s confession, the authorities had their doubts about his latest claim. By all accounts, there was very little evidence to connect Günter to Petra’s disappearance. Eventually the case went to court, but Günter was only convicted of the 14-year-old’s murder.

Images: YouTube/Aktenzeichen Laibachs Hoden-Wohl

But although the authorities did not believe that Günter had murdered Petra, they were still convinced that she had met with a grisly end. As a result, four years later, in 1989, the student was officially declared dead. And for more than three decades, her disappearance remained unsolved.

Then in September 2015 something incredible happened. In Düsseldorf, more than 200 miles from Petra’s former home in Braunschweig, police were alerted to a break-in at an apartment. And when they arrived on the scene, they found a woman named Petra Schneider living there.

However, when the police asked for her documents, the woman was unable to prove that she was indeed Ms. Schneider. In fact, she appeared to have no identification whatsoever – no ID card or passport and not even a bank account or insurance certificate in her name.

Images: YouTube/Aktenzeichen Laibachs Hoden-Wohl

Eventually, the woman made a startling confession. Under pressure from the officers, she admitted that she was in fact Petra Pazsitka – the same woman who had gone missing 31 years earlier. Amazingly, she was even able to produce old documents that confirmed her identity.

Gradually, a bizarre story began to emerge. According to the woman, she had planned her own disappearance from Braunschweig, saving up some 4,000 Deutschmarks in order to start a new life. In today’s money, that’s the equivalent of more than $2,000.

The woman claimed that after disappearing from Braunschweig, she moved to a rented apartment in Gelsenkirchen, a city some 35 miles northeast of Düsseldorf. From there, she had traveled across the country before finally settling in Düsseldorf. Indeed, by the time that the police arrived on her doorstep, she’d been living in the city for 11 years.

Yet how had the woman managed to survive for 31 years without any official documentation? Reportedly, police believe that she had been employed illegally, although they did not disclose the nature of her work. “She did not have a bank account and paid all her bills in cash,” Joachim Grande, of the Braunschweig police department, said in a 2015 interview with the Daily Mail.

Meanwhile, the woman appeared to have done everything she could to remain off the radar. Police claimed that she’d had little contact with her neighbors in Düsseldorf, preferring instead to keep to her own company. Moreover, even though her identity had now been discovered, she seemed to show no interest in reuniting with those she had left behind.

“Her family is devastated,” a police spokesman subsequently told the Independent. “We are trying to arrange a reunion, but Petra P is adamant that she does not want any contact with them.” Apparently, officers were also able to rule out any abuse or violence in her past. So why did this young student give up everything to live a life of anonymity outside of the law? The truth may never be known.