Mosquitoes in Finland "pave the way" for the police to solve the case, help hunt down the offender

This is the story of how a small mosquito proved to be the key to solving a car theft in Finland, leaving a remarkable mark in the annals of forensic science.

One clear morning in Finland in 2008, police officers in Seinajoki inspect a newly recovered stolen car. Frustration was evident on their faces as the usual clues such as fingerprints, witnesses and alibis yielded no results in finding the car thief. However, a small mosquito discovered opened up a new dimension in the investigation.

After observing and seeing the mosquito appear to be tight, this could not help but make the policemen trust the whispering of intuition. In their minds came the question: what if mosquitoes have bitten the culprit? And what if, thanks to the miracles of modern science, the amount of blood carried by the mosquito could hold the key to identifying the thief?

Soon after, these police officers sent the mosquito to the National Bureau of Investigation in Helsinki for DNA analysis from the mosquito's blood. The results showed that DNA records matched a suspect already in a police database of other crimes. This demonstrates the magic of forensic science and the ability to use mosquitoes as an important tool in criminal investigations.

"The use of mosquitoes in investigations is uncommon. During our training, we weren't taught to keep an eye on mosquitoes at crime scenes," Palomaki said.

He added: "It's not easy to find a small mosquito in a car, which just goes to show how thorough the crime scene investigation is."

The suspect denied stealing the car and insisted he was only hitchhiking with one man. However, with this newly found evidence, police were able to arrest the suspect. Years later, it remains unclear whether the person will eventually be convicted.

One study found that it was possible to separate human DNA from mosquito blood. A mosquito can feed on blood within 106m of a location and can only fly as far as 170m. This means that mosquitoes within a certain range of a crime scene can provide evidence to identify the culprit. In fact, solving cases thanks to mosquitoes also appears in other parts of the world.

A similar case has occurred in China. Specifically, in 2022, the police of Fuzhou City, Fujian Province announced a rare case on the social network WeChat. Police on June 11 received a report of a burglary breaking and entering and taking away valuables at an apartment in Fuzhou.

When police searched the scene, they found the burglar had broken into the apartment from a balcony. Once inside the apartment, he cooked egg noodles to eat before burning mosquito incense, covered himself with his host's blanket and slept through the night.

The investigation team found nothing but blood stains from a mosquito lying flat on the wall, they decided to take a blood sample for DNA testing.

DNA tests showed that the blood belonged to a man surnamed Chai, who had several previous convictions. 19 days after the burglary, Chai was taken in for questioning and he confessed to this and three other burglaries in which he was a suspect.