The Role of Forensic Virology in Crime Investigation
Forensic virology is a recent ramification of forensic microbiology that employs the study of viruses to help solve criminal investigation cases. As this is an emerging forensic science, several studies are still being conducted to perfect the right methodologies and overall application processes.
However, several investigations have demonstrated that virology studies can be invaluable in different forensic contexts. Tracing a suspect’s infection history, individual identification, and determining the source of pathogens used as bioweapons are a few examples of the most prominent examples of how viruses can be helpful in crime investigations.
In this article, we’ll be going over all of these practical examples of forensic virology applications. We’ll also take a closer look at how artificial intelligence can be combined with forensic virology to improve its efficacy in modern times.
The Role of Forensic Virology in Crime Investigation — Practical Examples
So far, the main investigations regarding forensic virology applications have focused on tracing infection history in humans, identifying suspects of sexual assault, and determining the source of bioweapons.
In the following sections, we’ll be taking a closer look at each of these applications and explaining how studying viruses can lead investigators in the right direction during crime science investigations.
Tracing Infection History
Several human viruses can chronically embed themselves in our cells and tissues, after an infection. Some of these viruses are acquired during childhood years and continue to persist in their host until they no longer live.
A study conducted in 2016 allowed investigators to understand that these viruses also have discrete geographical distributions, with certain strains associated with specific regions and populations.
An individual from the United States was infected with two different strains of the herpes simplex virus type 1 (HSV-1), which causes the common lip cold sore. These strains originated from two different continents, allowing researchers to trace the individual’s travel history.
Since there are different HSV-1 strains from Africa, Asia, and Europe/North America, it’s possible to predict an individual’s geographical origin as well, which can be helpful during criminal investigations, to narrow down the pool of suspects, for example.
Another forensic implication of studying this virus is that two people infected with identical strains of HSV-1 are more likely to be related than people who have different strains. This is an extra layer of information that can be acquired in situations where DNA analysis isn’t viable.
Study researcher Derek Gatherer said in the article release: “Forensic virology could be on the way in the same way in which we use genetic fingerprinting of our human DNA to locate perpetrators at the scene of a crime and to help trace the relatives of unidentified bodies.”
Identifying Suspects of Sexual Assault
Whenever unprotected sexual assault occurs, there’s a chance that transferral of a sexually transmitted disease might occur. Different studies have shown that the human microbiome and virome differ between regions of the body and may prove useful for determining the nature of stains.
Some studies also note that it might even be possible to link the stains (like vaginal fluid, semen, or saliva) to the person responsible for them. For example, when a viral infection is transmitted as a consequence of a sexual assault, the virus’ phylogenetic profile might help link the assailant and the victim.
There are, in particular, a few cases that involved the transmission of HIV in which the construction of the phylogenetic profile of the virus, using maximum likelihood methods, and assessments of the V3-V5 regions of the HIV genome helped identify the perpetrator.
Determining the Source of Bioweapons
Over the last few decades, an increase in international travel, growing populations, and urban development has led to the expansion of emerging and reemerging infectious disease threats, as they provide the ideal conditions for viruses and other microorganisms to evolve and disseminate.
Bioterrorism is the intentional release of viruses and other germs that can infect people and sicken them. A few cases of bioterrorism were extremely significant throughout history, namely the dissemination of anthrax spores as a bioweapon delivered through the US postal system, in
2001.
Viruses like variola and ebola are currently at the top of the list as potential bioweapons. They pose a great cause for concern due to the severity of the infection which can cause severe disease and death.
Forensic virology is extremely useful in bioterrorism situations as it can help determine the cause and source of the transmission of the bioweapon. Experts in infectious disease pathology can quickly identify the virus behind the infection and forensic virologists can perform genotype analysis to determine the geographical origin of the strain used.
Human Identification Using Skin Virome Samples
Different studies have determined that different microbes colonize different areas of our bodies. The microbes in the skin, for instance, are so specific to each individual that they could be used as a source of identification in the absence of other viable DNA samples.
Unfortunately, the human skin microbiome is affected by many confounding factors like antibiotics or the use of antibacterial soap. This is why researchers are now turning to the investigation of the skin virome.
The viral populations that are a part of the core skin virome offer stable biomarkers that allow for detection and identification even in the presence of outside environmental disruptive factors.
So far, 59 putative markers were found in the human skin virome that could potentially be used for discriminating individuals within the population.
This could be extremely useful in the context of forensic virology in missing person cases or in criminal cases in which investigators might have a viral sample from a crime scene that needs to be matched with a sample from a suspect.
Virology and Artificial Intelligence
The emergence of new artificial intelligence techniques is extremely important to the development of new methodologies in virology studies.
For instance, considering how impactful the COVID-19 pandemic was, new AI and machine learning models were developed to predict the likelihood that any animal-infecting virus will migrate to infect humans.
The importance of these new models in predictive medicine and public health is undeniable. However, there are also some new developments when it comes to the combination of artificial intelligence and forensic virology.
Decision Trees and Random Forests are two AI algorithms with great predicting capabilities. When applied to forensic virology, these classifiers can help predict the diagnosis and outcome of an illness caused by a viral infection in sexual assault cases.
Deep neural network algorithms include image processing and facial recognition. They use pattern matching (convolution) and aggregation (pooling) operations as their basic cores.
Potential use of these algorithms in the context of forensic virology could be the development of image-processing convolution neural network algorithms for the prediction of viral proteins that could help identify potential suspects.
The Role of Forensic Virology in Crime Investigation — Final Considerations
The study of viruses in the context of forensic sciences has led to the development of a new ramification of forensic microbiology: the field of forensic virology. Here, the knowledge of viruses is applied to criminal justice to help investigators solve their cases.
Tracing infection history, identifying suspects of sexual assault, determining the source of potential bioweapons, and identifying individuals through their skin virome are some of the forensic applications of virology.
The advent of artificial intelligence and machine learning algorithms has also led to the development of new methodologies that could be employed in forensic virology cases.
Decision Trees, Random Forests, and deep neural network algorithms can help predict the diagnosis and outcome of an illness caused by a viral infection in sexual assault cases and even discover viral proteins through facial recognition that could help identify potential suspects.
