How fingerprints and other biometrics help law enforcement
Law enforcement agencies around the globe have been embracing the possibilities of biometric technology for a long time. The first fingerprint for criminal identification was taken in 1892 in Argentina. Nowadays, police forces are challenged to become more efficient. At the frontline, first responders need to rely on speed and accuracy.
Biometrics in today's law enforcement
Each time we touch our phone, car door or computer keyboard, we leave behind our signature. No two people have the exact same finger print. Our uniqueness makes it a reliable method to be used in all sorts of ways including identification and background checks.
Automated Fingerprint Identification Systems are used for storing and processing fingerprints. Digital fingerprints can be compared to those recorded in the database. AFIS is used for two specific biometric methods: fingerprint identification and fingerprint verification.
Tenprints represent a complete set of fingerprints collected on a single sheet. The identity of the person is known, making it a ‘known print’. Today, fingerprints are taken by a scanner, replacing the traditional ink pad. Latent prints are recovered from a crime scene by using chemical and lighting techniques.
Palm prints can be collected using a similar method to fingerprints and can also be used for identification by forensics.
The human touch
Simply relying on the algorithms of AFIS is not enough to conclude an investigation. The human factor is still crucial. The clarity of the image and the minutiae features are reviewed manually in order to determine what to focus on.
DNA is a powerful tool for law enforcement investigations. Each person’s DNA is different, except for identical twins. By analysing DNA sequences or loci (location in the body), forensics can develop a profile that can help identify a suspect.
Each cell in the body has an inner core, a nucleus that holds chromosomes. The chromosome contains markers that repeat DNA sequences. It varies how many times a sequence repeats, depending on the person.
The first step in DNA profiling is to obtain samples. Only a small number of cells is needed to build the unique profile. From these cells, DNA is extracted and copied. After this process, forensics generates a DNA profiling definition that law enforcement professionals can read.
The rise of databases supported the increased use of DNA profiling. For example, INTERPOL’s DNA database contains more than 247,000 profiles.
The methodology is a very practical and precise method. Although it is very accurate, it is never foolproof. A partial profile could match with multiple people for example and can’t serve as a conclusive piece of evidence.
Both voice and facial recognition tools serve a variety of purposes such as investigative leads and the identification of crime victims.
Facial recognition technology is a complex software, comparing a picture of a suspect’s face to others in a database. By using algorithms, the system can pick out specific and distinctive details about a person’s face. These details are converted into a mathematical representation and compared to the existing data.
The first speech recognition platforms were developed in the 1950s and could only understand digits. Today’s solutions are much more advanced and accurate, recognising accents and environments with background noise. Reporting and documentation are essential elements of law enforcement and speech recognition technology (SRT) makes that process easier and faster.
The use of facial recognition by police forces can be a topic of discussion for lawmakers, political parties, and the public. Take surveillance for example. The UK’s Information Commissioner’s Office launched an investigation on the use of facial recognition after it became known that the general public was having their faces scanned without consent.
For facial recognition algorithms to work well, the system must be trained and tested with large data sets with images captured under different conditions. This raises ethical questions on how data is collected, stored, shared and used.