Facial Recognition for Verification (Missing Persons)

Facial recognition (FR) is a controversial technology. People's privacy, attribution & freedoms are often questions when FR is advertised as being used to identify someone, such as transiting through airports, online via social media, or CCTV tracking at venues. However, like any technology, the intent is what really matters as this technology is publically available for developers to build solutions around.

In this article, we're going to focus on how FR can be used to support missing person investigations. Trace Labs (https://www.tracelabs.org), NCPTF (https://ncptf.org) & many other organizations are doing amazing work around the world to help law enforcement & families, and often during missing person investigations an investigator may come across multiple profiles, sometimes dozens and photos that you think are associated with your subject but you are uncertain if it really is the subject. This article focuses on simple methods to support the verification process.

This is where FR comes into play. We can leverage artificial intelligence to support our investigations using simple, easy to use & free tools. To be clear, we are not trying to use FR for scale & reverse locating other profiles here, such as tools like Primeyes, we are using it specifically to support positive identification of a subject against another image.

Why?

Verification. Providing leads for law enforcement as part of crowdsourced information, or for law enforcement specifically who are tasked with conducting the investigations themselves, verification is always of extreme importance. We can use technology to support that verification process. Importantly, this is only a very small part of the process, but it can create efficiencies when trying to positively identify a subject against a social media profile.

Tools

Amongst others, Google, Amazon & Microsoft all offer free tools to "sample" FR technology. These tools are enough for us to achieve our tasks that we're covering in this article. However, they differ in capabilities. For example, Google performs "Face Detection" but Amazon & Microsoft provide "Face Comparison" capabilities. This is important to note as we are focusing on facial comparisons.

Microsoft Cognitive Services

The first tool we have available is the Microsoft Face Verification tool. Available here: https://azure.microsoft.com/en-au/services/cognitive-services/face/#demo

As you can see, the tool is very user friendly & provides a simple way to compare images to provide a confidence score. The benefit of Microsoft's tool is that it does not require a login to access.

Amazon Rekognition

To access the Amazon technology, you will need to login to the AWS Console (after creating an account) at https://aws.amazon.com/console then search for "Rekognition" & access the free sample tool there.

Once in the tool, click the "Try Demo" then "Face Comparison" link on the left-hand navigation pane, then upload your source image & comparison image.

Whilst more restrictive to access quickly, FR technology & the datasets that were used as part of the machine learning (ML) process differ from company to company. Therefore, it is beneficial to use multiple platforms to add another layer of verification to the process for comparative analysis.

Use Case

Let's apply this to a real missing person case to see some of the utility. We will look at the missing person case related to Logan Shearburn (https://www.namus.gov/MissingPersons/Case#/69693?nav)

We are assuming that investigators will search across prominent social media platforms to identify associated profiles. In this example, we will search on Instagram & identify that there are multiple profiles that could be related to the subject. Each of these may have valuable clues & associates which feed into the information chain for further analysis.