10 years after the Rupperswil case Why the perpetrator would be caught faster today thanks to new technology

A cell phone in flight mode, in the wrong place at the wrong time - and a murderer is caught. Today, the police would strike even faster than ten years ago because technology and investigations have become much more precise.

On December 21, 2015 , the then 33-year-old Thomas N. killed a woman, her two sons and the older son's girlfriend in Rupperswil. For a long time, it was unclear who the perpetrator was and the police searched for him at full speed. Then, five months later, the handcuffs clicked in a Starbucks branch. Investigators said at the time that Thomas N. had googled his later victims several times before the crime. The data trail had led to his IP address.

One thing in particular has been clearly proven: the so-called antenna search provided a decisive clue. This refers to the query of which cell phones are or were connected to a specific cell phone antenna.

Figures from the surveillance statistics show that the canton of Aargau ordered three such searches for murder in the year of the crime. They showed that Thomas N. was repeatedly in the vicinity of the victims' house before the crime - and suddenly switched his cell phone to flight mode on the day of the crime. This conspicuous behavior made him a suspect. He was arrested shortly afterwards.

How would the police proceed today? Would they be quicker? blue News spoke to several people from the tech scene. The answer is clear: yes. Not only is the technology more advanced, but investigative work is also organized differently today.

5G delivers fewer innocents

Antenna searches continue to play a central role. This involves determining which cell phones were connected to a radio cell at a certain time. Depending on the location of the crime, several dozen or several thousand numbers can be recorded.

"The decisive difference today is the size of these radio cells," says Marc Ruef, who has been researching cybersecurity since the late 1990s. The 5G standard uses different frequencies than 3G used to: they transmit more data, but are attenuated more quickly by walls, terrain or vegetation.

This has positive consequences for investigations: The radio cells are smaller. "If an antenna is close to the crime scene, an antenna search with 5G produces significantly fewer hits," explains Ruef. For the police, this means fewer people who need to be checked - and a quicker narrow-down. "5G enables a more precise location."

However, the progress is not only in the infrastructure, but also in the police processes. "Antenna searches are no longer a special tactic that someone has to suggest first," says Ruef. "It is standard." This is also confirmed by figures from surveillance practice: the tools are being used more frequently and more routinely.

AI helps to localize photos

The situation is similar when it comes to cooperation with tech companies. In the case of Thomas N., Google search queries are said to have played a role. Today, contacts between law enforcement agencies and platforms are much better coordinated, several sources confirm.

However, there are still challenges. "Many people are now more aware of their digital footprints," says Ruef. In the past, photos were often shared on social networks along with their location, time and other data. This digital "location waste" has become much smaller.

But it hasn't disappeared. And this is where new tools come into play: artificial intelligence can provide investigators with clues, for example by recognizing where a photo was taken based on the landscape, plants or buildings. "Even without location information, images can sometimes be classified surprisingly well," says Ruef.

To summarize: if the Rupperswil case were to happen today, the police would immediately use an antenna search as an investigative tactic - and thanks to 5G, they would obtain even more precise data. Communication with platforms such as Google would also be more coordinated, which would save valuable time.