Matthias Monroy

The German police are increasingly using photographs to name unknown persons. More and more, pictures from social networks are being used. Recognition is also possible if the persons are wearing a protective mouth-nose mask. Some authorities also use so-called super-recognisers.

A growing number of people are being identified by German police forces with the help of facial recognition. Since 2018, they have doubled every year; in 2020, this amounted to 4,403 people. This is what the Federal Ministry of the Interior writes in its answer to a written question on the police facial recognition system (GES). Around one third of those affected were named by the Federal Police.

Since 2008, the GES has been centrally managed by the Federal Criminal Police Office and is available to the Federal Police and all 16 State Criminal Police Offices. A query can be made if a person is a suspect but his or her name is not known. The type of offence charged is irrelevant; the system can also be searched in the case of an insult or shoplifting.

Use also for shoplifting

For the searches, the police use photos or still images from video cameras on which the alleged offender is depicted. In the GES, an algorithm then selects images with the highest match. They are checked by the investigators against the photo of the unknown suspect.

The GES software queries the central police information system (INPOL-Z), which is also located at the BKA. The searchable images in this largest German police database originate mainly from a recognition service treatment that can be carried out after an arrest. Currently, about 5.8 million portrait photos of 3.6 million people are stored there. This number is dynamic, older photos are deleted, new ones are added. In 2020, about 740,000 images were removed and 649,000 added.

According to the Bavarian State Criminal Police Office, the GES is increasingly using images from social networks for the query. The facial recognition is also supposed to work if the persons being searched are wearing a mouth-nose protective mask in the photo.

Training light „photograph experts“

The GES comes from the Dresden-based company Cognitech. Two years ago, the BKA commissioned a „performance comparison“ to compare the aging system with software from other vendors, including NEC, AnyVision, Idemia and VisionLabs. All applications use „machine learning methods“, according to the Federal Ministry of the Interior. The investigations were completed a year ago, and no new procurement has taken place so far.

In an earlier answer, the Ministry of the Interior had also provided the numbers of searches. In total, the GES was queried 76,535 times last year, about half of these accesses were made by the BKA. Around 31,000 searches came from the state criminal investigation offices. 4,574 queries were made by the Federal Police in 2020. There was confusion about this number because it was previously given as 4,024.

The ministry explains the contradiction by saying that the higher number is due to the „technical survey in the system“. All accesses are counted, regardless of the purpose. This also includes those queries that are not carried out for investigative procedures, but in the context of training „photograph experts“.

Human super-recognition

In addition to computer-assisted facial recognition, more and more police forces are also using so-called super-recognisers. These are one to two percent of the population who are particularly good at remembering faces and recognising them in crowds. This was discovered by the British scientist Josh Davis during a study within the Metropolitan Police. At the request of the police in North Rhine-Westphalia, the British officers first helped solve crimes in Germany in Cologne after New Year’s Eve 2015/16.

Afterwards, Davis helped the police in Bavaria to set up such a unit, which is said to have helped solve hundreds of cases in the meantime. Since 2018, Baden-Württemberg has also identified several super-recognisers in its own ranks. The humanoid facial recognition was used in Munich after the Oktoberfest and in Stuttgart after the „riot night“ there a year ago. Six Bavarian officers supported the police in Hamburg in their search for suspected criminals after the G20 summit in 2017. After Berlin, Saxony is also planning a corresponding pilot project.

Like the GES in the BKA, the super-recognisers can allegedly recognise people if they change their appearance with a cap, beard, sunglasses or paint. According to the Bavarian police, they successfully demonstrated this when handling protests against the further construction of the A49 in Dannenröder Forst. The unit then trained 45 Frankfurt officers, who will now also be used for super-recognition.

Image: The facial recognition system of German police forces allegedly works even if the persons concerned wear a mask, as in Dannenröder Forst (Channoh Peepovicz).