Police officers were taken by surprise when they went to gather evidence following a house robbery in the western German city of Düsseldorf. The 55-year-old woman, known as Petra P., told the officers that the name on the house door wasn't hers and that she was actually the student from Braunschweig who had gone missing over 30 years ago.

The woman also used her old, expired identity card to prove her identity. Local police told reporters that their officers had spoken to her and asked her specific questions to ascertain whether she was the same student who disappeared in 1985 and was thought to be murdered.

Petra P. said she spent the last 11 years in Düsseldorf and before that she was in many places about which "she does not know anymore." The authorities were baffled by how the 55-year-old managed to survive without a social security card, a passport, a drivers' license or a bank account for all these years.

Petra P. never had to show her official documents and she worked to earn a living, police spokesman Joachim Grande told reporters. "She cannot be made criminally liable," he said, adding that she did not use false papers.

German newspaper "Tagesspiegel" posted a picture of the woman on Twitter.

An unsolved mystery

Petra P. went missing in 1984 in the area around Braunschweig/Wolfsburg. She was living in a student hostel at the time and studying information technology. She had finished writing her university thesis on computer languages. On July 26, 1984, Petra went to the dentist and was supposed to take the bus to Wolfsburg to meet her parents. But she did not go home. Her brother registered her as missing with the police a few days later.

Investigators assumed she had been attacked, but by 1985 they had found no trace of the victim. They also broadcast requests for clues in the television show "Aktenzeichen XY…ungelöst" [File number XY..unsolved]" which asked for public information in cases which the police found difficult to solve.

Some years later, the murderer of a 14-year-old student admitted to killing Petra P. as well and she was finally declared dead in 1989.

Now, after being gone 31 years and "dead" for 26 of them, Petra P. will have to be declared alive by the state prosecutor's office in Braunschweig, also known as Brunswick in English. She has said she does not want to divulge any details of her life to the media and does not want to contact her relatives. Police have, however, informed her family.

mg/sms (dpa, police)