DNA in criminology

These rapists and murderers were tracked down decades later thanks to DNA and genealogical sites

Vitaliy Olekhnovich, Onlíner

There are no recordings from surveillance cameras, no witnesses, no suspect or motive — only a few hairs that may belong to the attacker are found at the crime scene. Even 20 years ago, this would hardly have led to the detection of a crime. Today, some companies assure that they can recreate the killer's face using DNA.

Experts from the Israeli company Corsight AI claim that they are able to create a model of a face based on a DNA sample left at the crime scene. Then this model can be run through the facial recognition system and thus get to the suspect. The corresponding slide was seen at the company's presentation to investors in December last year. The firm, whose advisory board includes a former CIA director and an ex-FBI assistant director, is going to "build a physical profile by analyzing genetic material collected in a DNA sample."

From a scientific point of view, this sounds impossible, even if DNA has been experiencing a second flowering in criminology in the last few years thanks to genealogical sites. However, the ambitious signal indicates that facial recognition systems are ready to rely even on inaccurate means, just to identify a person by any means.

The idea doesn't work?

The Israelis from Corsight AI are not the first to want to link a person's face to his genome. Five years ago, Silicon Valley startup Human Longevity set a similar goal. A semi-scientific work has even been published on this score. However, experts soon discovered that technically incorrect indicators were used in the work and the system itself could not identify a person by the human genome.

The company Parabon NanoLabs presents to law enforcement officers three-dimensional images of people's faces based on the genome and a set of phenotypic characteristics (eye or skin color), which may have their own rather small confidence index of less than 80%. Genome-based portraits are being refined by forensic experts based on non-genetic factors (weight or age, when possible).

Parabon has a website where the company confidently claims that its employees have helped solve more than 200 cases. There you can also see a comparison of photos of already caught criminals with the visualization made by Parabon NanoLabs specialists. As you can see, there is not always at least a distant similarity between computer visualization and the real picture of the criminal.

Ellen McRae Greytak, director of bioinformatics at Parabon NanoLabs, however, responsibly states that the company's methods are far from perfect: "Technology won't tell you the exact number of millimeters between the eyes or the ratio between the eyes, nose and mouth." To create such precise algorithms, fundamentally new scientific discoveries will be required, and so far the company only predicts the general shape of the face. Although these predictions, as we see, are not accurate enough.

In many ways, this happens because to obtain accurate characteristics based on genes, there is still not enough information about the genes themselves and their effect on a person's appearance. In addition, the environment and aging have a significant impact on faces that cannot be drawn using DNA phenotyping.

There is an opposite approach — from the face to the DNA. In 2019, a group of scientists from the Netherlands compared a set of 3D images with DNA samples. They managed to achieve accuracy in the region of 80-83%. It would seem that the prospects for such methods are quite good. However, in criminology, such a high chance of failure means that an innocent person may be under investigation.

The task of justice is to punish the guilty, despite how many years have passed and how much he has changed. And then law enforcement agencies, along with DNA, come to the aid of sites to search for relatives and roots.

Rapists pop up

In 2018, the dramatic arrest of 72-year-old Joseph James Deangelo raised many questions about the use of genetic information and commercial databases intended for completely different purposes. Deangelo turned out to be a serial killer and rapist who had terrorized California for a decade since the mid-1970s.

Evidence from the scenes of his crimes has been kept in police archives for a long time. At the beginning of 2018, Detective Paul Holes realized that services such as GEDmatch, which help to find relatives and build a family tree based on DNA information, could be the key to uncovering the "capercaillie". First, he checked how it worked using his family's DNA profiles, and then decided to send information about the DNA of the killer from the Golden State to the website. Of course, the service did not immediately point to the suspect, but helped to find his possible distant relatives. Through them, law enforcement officers got to Deangelo. The old man was sentenced to 26 life sentences, he confessed everything.

The first sequencing of the entire human genome took more than ten years, cost about $3 billion and was completed in 2003. Less than a decade has passed since millions of people were able to use modern equipment to decipher their genotype in pursuit of roots. In the USA, a country of migrants, this caused a real boom. A bunch of services appeared that accumulated DNA profiles of Americans and built their family trees. These are the resources that law enforcement officers are using now.

As it turned out later, the detectives' efforts to match DNA were more extensive and included secret searches for private DNA stored in two commercial companies, despite their privacy policies. This, in turn, provoked a debate about genetic privacy, self-control of testing companies and access to such information by law enforcement.

First, the detectives sent DNA materials to FamilyTreeDNA, where they were allowed to create a fake profile to search for matches. When this gave only distant clues, a civilian geneticist working with the investigation uploaded a profile to the MyHeritage website. It was there that they managed to find a close relative of the serial killer, who helped solve the case. Representatives of the service stated that their security policy does not provide for direct and such unprecedented access by the police. The search was not authorized, they tried to hide this information from the general public, and it was revealed only in court materials.

The legality of investigative genealogy leaves many questions. Although in the law enforcement agencies of advanced countries it is considered a vital tool for solving crimes, but the law does not have time for this tool.

For example, technology led to the conviction of Roy Charles Waller, a serial rapist who committed 46 rapes from 1991 to 2006. As in the case of Deangelo, Waller was tracked down by DNA traces found at the crime scene.

A profile based on this DNA through the GEDmatch website led to a relative of Waller, through whose family tree the suspect was calculated. His DNA, obtained by the police, matched samples from the crime scenes of a rapist from Northern California. Waller, who successfully hid from the police for 14 years since the last crime, was sentenced to 897 years in prison.

The mystery of 42 years ago was solved in Las Vegas. In January 1979, a 16-year-old girl disappeared there. A month later, her body was found in the desert. The unknown raped and killed her.

42 years later, Las Vegas resident Justin Wu made a financial donation to the Othram laboratory and asked the police to continue the investigation using advanced technology. Genome sequencing, and then a search through the genealogical database, have borne fruit.

The killer turned out to be then 19-year-old Johnny Blake Peterson. Unfortunately, he himself died in 1993.

The police at a briefing on the case said: "We can take those cases in which all other methods did not help. We can still solve them. These families still have hope. No one should have to wait 42 years to find out who killed their child."

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