How is Facial Recognition Technology Used in Law Enforcement?

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A protester spray-painted a security camera in Hong Kong. Bild: Chris Mcgrath/Getty Images

Law enforcement around the world uses facial recognition technology to assist in their work. But how does facial recognition technology work and how can it affect you personally?

Face recognition by the Swedish Police

In Sweden, the police received approval to use facial recognition as late as October last year (2019). The aim is to use facial recognition technology to assist in investigations of crime and it’s planned to commence in the autumn of 2020.

Initially, it will first be introduced to law enforcement in larger cities for individual police investigations. The system will help the police analyze and categorize image-materials from ongoing investigations.

If you’re interested in reading more about the current Swedish development in this area you can read the police’s official statement here (in Swedish) > and a related new report here (in English) >

Article structure

This article will treat these following issues:

  1. What is facial recognition technology?
  2. How are facial recognition technologies used in your everyday life?
  3. What happens when the police start using facial recognition?
  4. Can the use of facial recognition by law enforcement impact you negatively?

1. What is facial recognition?

Facial recognition is a technology that makes it possible to match an image or video of a human face, to an image of a face in a database.

How does facial recognition work?

Apple Face ID explained

See the video for an explanation of how Face ID in Apple products work.

Do you want a shorter explanation?

In short, face recognition software needs to be able to locate and measure facial features from an image.

  1. To begin with, the computer system identifies a large number of points on a face (either through a live camera, a video, or image).
  2. Furthermore, AI is used to distinguish facial features. The program identifies things such as the location of the eyes and face shape.
  3. Finally, the pattern is matched with data from a database.

A database in this case can be a collection of images in an image library. This library may contain images of faces with associated personal details.

AI & Deep Learning for improved facial recognition

As stated, face recognition is a technology that is still evolving and constantly improving.

According to a relatively fresh report from NIST, there have been massive improvements in technology during the past few years (2013-2018).

But what is it then that has driven the technology forward?

The answer is that this development has primarily been achievable through the implementation of AI.

More specifically, techniques in deep learning and artificial neural networks have been implemented to make the programs smarter and faster.

For those of you who are curious to learn more, this video explains what Artificial Intelligence (AI), machine learning, and deep learning is:

2. Face recognition in everyday life

When it comes to the use of face recognition, it has already become a part of our everyday lives.

In some ways, it happens clearly, but it also happens in the hidden and without our knowledge.

And this happens despite the fact that it is still a technology that is under development. It’s a truly powerful and impactful technology.

That’s why it’s also quite likely that face recognition will only become more and more implemented in society.

Some examples of everyday uses of face recognition are:

  • Face ID on iPhones and Macbooks. And other similar services provided by other operators.
  • Queuing systems at modern airports where faces are scanned and automatically matched to the individual’s passport.
  • Smart features in mobiles and computers that identify and categorize faces among your private photos.
  • Without our knowledge, companies and states constantly collect information about us, even in the form of pictures of our faces.
    • Such data can then be sold and used to build databases containing our faces without our knowledge.
    • Private individuals can also build up such databases. Research study > is an interesting study by three master’s students who collected data on faces from Reddit and Twitter. The purpose of the study was to prove that there are opportunities for anyone to create their own facial databases.

In conclusion;

It’s everywhere.

3. What happens when the police use face recognition?

👍🏼 The benefits of police using facial recognition

The benefits of facial recognition for police work are clear. To detect and prevent crime.

For example in preliminary investigations where such technology can assist in identifying, categorizing, and linking image material.

But it can also be good for active work, such as tracking down dangerous people on the run.

1. Analysing videos from crime scenes & events

The Swedish police have not yet received approval or commented on using real-time facial recognition on surveillance cameras and the like.

But it is known that many modern face recognition programs can work with real-time surveillance camera footage. And that many other countries already implement such technology.

So it can only be a question before it happens.

However, the fact that such advanced technology already exists means that videos from surveillance cameras at crime scenes definitely can be used to identify criminals.

This also applies to videos from social media where you can see that a crime has taken place and faces are shown in the picture.

2. Identity document & protection

Another area of use is that police can use face recognition to issue identity documents and check identities. This can also be combined with other techniques such as fingerprints.

The technology already exists today and has already been implemented in US airports for passport controls for example.

The use of such technology by the police can therefore prevent identity theft and other identity crimes.

3. Face recognition from surveillance cameras

With the help of real-time facial recognition on surveillance cameras, the police can also succeed in things such as finding missing children and disoriented adults.

They can also identify and seek for criminals on the run. For example during ongoing terrorist attacks.

⚠️ Risks

However, there are many who are critical and concerned about government’s use of such technology.

Polisens ansiktsigenkänning och kameraövervakning
Image by Danny Lines

1. Risk of intrusion (hacking)

There is always a risk of intrusion into such systems and databases.

There is no guarantee that the state database will not be hacked and how secure everything will be.

Should such a thing happen, sensitive data could end up in the wrong hands.

2. In the future, the state may look different

There is also no guarantee that the state we have today, which in many western countries are democratic, law-abiding, and transparent, will remain that way.

And if it were to change, there could be a risk to us at an individual level.

An example of this is explained in the next paragraph.

Real-life example:
Face recognition during the Hong Kong protests

Face recognition and large databases can be a major threat to democracy.

This can happen if the data gets controlled by an organization or state that seeks to restrict democratic rights.

A real example is how facial recognition with AI is used to identify pro-democracy protests during the Hong Kong protests.

In the past year, there have been major protests in Hong Kong. This is because China has restricted Hong Kong’s democratic rights.

During the protests, it was discovered that the Chinese government probably used facial recognition on the surveillance cameras to identify protesters.

The incident in turn led to that protesters had to, and still need to, hide their identities.

This is done by wearing face masks, ski goggles, and using laser pointers to interfere with surveillance cameras.

What happened in Hong Kong is a real example of how camera surveillance and overall government data collection can negatively affect democracy.

masked protesters point lasers up to camera in hong kong, in an effort to thwart  facial recognition capacities.
Protesters in Hong Kong use laser pointers outside the Central Government complex after a march on August 18, 2019 .(Photo by Anthony Kwan/Getty Images)

Threat to democracy

Here you can read more about the Hong Kong protests:

4. How does face recognition by the police affect you?

To summarize:

  • Police use of face recognition improves security in the community and in your life.
    • This is because they will be able to identify and catch criminals more effectively.
  • But it comes with risks.
    • The data may end up in the wrong hands and in the future, our states may not remain as it is today and the data can be used for undesirable purposes.

But it is inevitable that the police will start using facial recognition, if they haven’t already.

We’ll have to wait and see how this develops.

Are you interested in reading more?

Here are a few book recommendations on this topic.

Note! These are Amazon affiliate links but my personal recommendations.

  1. Artificial Intelligence Dangers to Humanity
  2. The age of Surveillance Capitalism
  3. Our Final Invention: Artificial Intelligence and the End of the Human Era 
  4. Machine Learning Mathematics: Study Deep Learning Through Data Science. How to Build Artificial Intelligence

Here are a few related articles

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