Use of DNA phenotyping to solve crimes fraught with problems, critics say

Forensic DNA phenotyping (FDP) has emerged as a groundbreaking tool in criminal investigations, offering the potential to predict an individual’s physical appearance based solely on their genetic material. This technology aims to generate leads in cases where traditional methods have stalled, providing law enforcement with new avenues to pursue. However, the application of FDP is fraught with scientific, ethical, and legal challenges that warrant careful consideration.

Parabon NanoLabs, a biotechnology company based in Reston, Virginia, has been at the forefront of FDP through its Snapshot DNA Phenotyping Service. Launched in 2015, Snapshot claims to predict various physical traits, including eye color, hair color, skin tone, and even facial morphology, from DNA samples collected at crime scenes. The company emerged from computational and bioinformatics expertise initially aimed at therapeutic applications before pivoting towards forensic applications. It has worked closely with the U.S. Department of Defense and law enforcement agencies to refine and deploy this technology.

In February 2019, for example, the U.S. Army Mission and Installation Contracting Command issued a sole-source contract to Parabon for Snapshot Genetic Genealogy Analysis from data developed in a previous contracting action with Parabon which appears to have been made in September 2016.

The company asserts that its approach provides valuable investigative leads, helping solve cold cases and narrow down suspect pools, and has reported success in assisting law enforcement agencies to solve cold cases by providing composite sketches of potential suspects based on genetic material. In 2019, Parabon’s phenotyping and genetic genealogy analyses contributed to the identification of suspects in several decades-old cases, leading to convictions in subsequent years.

Despite these reported successes, the scientific community has expressed concerns regarding the validity and transparency of Parabon’s methods. Critics argue that the company’s proprietary algorithms have not undergone rigorous peer review, making it difficult to assess their accuracy and reliability. Moses Schanfield, a professor of forensic sciences at George Washington University, has highlighted the lack of publicly available performance data for Snapshot, emphasizing the need for independent validation.

Critics argue that the statistical models used by Parabon have not been subjected to rigorous independent peer review. Genetic expert Susan Walsh, an assistant professor in the School of Science at Indiana University Indianapolis, challenges the scientific rigor of Parabon’s approach. While forensic DNA phenotyping has made strides in predicting traits like eye and hair color with reasonable accuracy, predicting facial morphology remains highly contentious, she says.

Walsh’s concerns stem from the lack of transparency in Parabon’s methodology, as well as the risk that law enforcement may rely too heavily on potentially flawed or misleading phenotypic predictions, leading to wrongful accusations and reinforcing racial biases.

The tension between scientific rigor and law enforcement application is further complicated by the proprietary nature of Parabon’s methods. Unlike academic research, which undergoes peer review and is subject to scrutiny, Parabon’s algorithm remains a trade secret, making it impossible to independently verify its reliability. Parabon defends its approach by pointing to real-world case successes, but experts counter that this anecdotal evidence does not equate to scientific validation.

The predictive power of FDP varies among different human traits. While certain characteristics like eye and hair color can be inferred with reasonable accuracy due to well-understood genetic associations, predicting complex traits like facial structure is significantly more challenging. The relationship between genetics and facial morphology involves numerous genes and environmental factors, resulting in predictions that are often imprecise. This imprecision raises concerns about the potential for misidentification and wrongful accusations if such composite sketches are relied upon heavily in criminal investigations.

Beyond scientific validity, FDP poses substantial ethical and legal dilemmas. One major concern is the potential infringement on individual privacy rights. DNA contains sensitive information not only about an individual’s physical traits but also about their health predispositions and familial relationships. The use of genetic data to predict appearance without consent can be seen as a violation of privacy, especially when such data is obtained from public genealogy databases. The case of the Golden State Killer’s apprehension in 2018, which involved uploading crime scene DNA to a public genealogy database, sparked a debate over the balance between public safety and individual privacy rights.

Another ethical issue is the potential for reinforcing racial biases. FDP often involves predicting biogeographical ancestry to infer physical traits, which can inadvertently lead to racial profiling. Given the complex relationship between genetics, race, and appearance, there is a risk that FDP could perpetuate stereotypes or result in discriminatory practices if not applied cautiously. Empirical research has underscored the importance of implementing proper regulatory frameworks to minimize risks of privacy violations and ethnic discrimination in the use of FDP.

The legal landscape surrounding FDP is still evolving. Currently, there is a lack of comprehensive regulations governing the use of FDP in criminal investigations. This regulatory gap raises questions about the admissibility of FDP-based evidence in court and the standards required for its use. Legal scholars have called for clear guidelines to ensure that FDP is applied responsibly, with due consideration for the rights of individuals and the integrity of the judicial process.

In response to these challenges, some experts advocate for a cautious and transparent approach to the use of FDP. They recommend that FDP should be employed only when there is robust, peer-reviewed scientific evidence supporting its accuracy for specific traits. Additionally, there should be clear policies regarding consent and data usage, particularly when dealing with genetic information from public databases. Transparency in methodology and openness to independent validation are also crucial to build public trust and ensure the ethical application of FDP.

The debate over FDP reflects broader tensions between technological innovation and ethical responsibility in forensic science. While FDP offers promising tools for advancing criminal investigations, it also necessitates a careful balancing act to protect individual rights and maintain public trust. As this technology continues to evolve, ongoing dialogue among scientists, ethicists, legal experts, and the public will be essential to navigate the complex landscape of forensic genetics responsibly.

The broader context of forensic DNA analysis, as detailed in Making Sense of Forensic Genetics, underscores the limitations and potential for misinterpretation of DNA evidence. DNA, while a powerful forensic tool, is not infallible and must be used within a framework of corroborating evidence.

Forensic DNA phenotyping represents a significant advancement in the field of forensic science, with the potential to aid in solving crimes that have remained unresolved for years. But its application must be tempered with rigorous scientific validation, ethical considerations, and appropriate legal frameworks to ensure that the pursuit of justice does not come at the expense of individual rights and societal values.

Article Topics

biometric identification  |  biometric identifiers  |  biometrics  |  criminal ID  |  dna  |  DNA phenotyping  |  forensics  |  law enforcement  |  Parabon NanoLabs