This case was regarded as a great shame by the German police. 16 What was the result of pursuing the mysterious female killer?

The police can't let go of clues when handling a case, and any small mistake will affect the case. Germany is famous for its meticulousness, and the legend of "sewer of German conscience" is still circulating in China. However, the German police spent 16 years tracking down a female killer who committed several major crimes, and found her dna every time, but failed to catch anyone every time. Finally, the police found that they had made a mistake from beginning to end. Do you know what this mistake is?

1On May 26th, 993, a 62-year-old woman was strangled by a metal wire at home. German police thought it was a murder case, but found nothing suspicious except the female dna in the cup that did not belong to the old woman. The police found that the dna database in Germany did not contain this dna, and judged that the murderer of the old lady was a foreign woman. Because I don't know what I look like, I am called a "faceless killer".

The "faceless killer" is so cunning that the police haven't found it for eight years. Moreover, in March of 200 1 year, she committed another crime. This time, the deceased was an antique owner, aged 6 1. In less than half a year, in June+10, 5438, the "faceless killer" killed a third person. The police found her dna on a bloody syringe. She must be an addict.

According to the information and dna, the police guessed her appearance, drew her and offered a reward of 300,000 euros. Although the police have painted portraits and offered a reward of 300,000 euros, the "faceless killer" simply ignored them. In 2007, he also killed a drug policeman. The German police were completely angry and directly raised the reward of 300,000 euros to 7 million euros.

From the first case of 1993 to 2007, the "faceless killer" committed at least four lives, as well as more than a dozen cases of theft and arson, and committed crimes in many countries at the same time. The police also feel very strange, why is the "faceless killer" so arrogant, so many high-profile crimes have not been caught, how can he commit crimes in multiple countries at the same time?

In 2009, the police found the dna of a suicide man. This time, the police began to wonder if there was something wrong with the cotton swab they collected dna from. The investigation results of cotton swabs came out, which shocked the German police. The problem really lies in the cotton swab.

The cotton swabs handled by the German police come from the Austrian cotton swab factory Greiner Bio-One. A female worker did not strictly abide by the rules and left her dna on a cotton swab. The cotton swabs she made were sold all over the world, and naturally some of them went to the German police station, which affected their investigation of the case. After the truth came out, the German police realized that the "faceless killer" that took 16 years to trace turned out to be a cotton swab, and they did not need to be accused by the public. They were all humiliated.

The German police learned this painful lesson and strictly controlled the police equipment afterwards. Germany has always been a serious country in our impression, but this time it was negligent and made a big joke. Moreover, more than a decade ago, some murderers who really committed murder and theft were at large because of cotton swabs, causing countless losses. We should also take the German police as a negative example to remind ourselves not to ignore the details.