Unraveling the path of infection using classical evolutionary biology techniques and modern genetic sequencing is a method that is increasingly being used in criminal and civil investigations. It is known as phylogenetic analysis but, unlike DNA tests, which are very common in legal proceedings, these results are rarely 100% conclusive.
Phylogenetics itself is a method of reconstructing the history of life, creating the genealogy of the virus and allowing scientists to predict how likely it is that two or more infections are related and what their relationship is; but this also brings many social concerns. In fact, critics of this technique claim that tracing the route of infection can further stigmatize diseases such as AIDS.
But it is no less true that this valuable information is a great tool for justice. Intentional infections , such as the one carried out in Valencia by the anesthetist Juan Maeso, who transmitted the hepatitis C virus to 275 patients and was sentenced to 1,933 years in prison, or that of Richard Schmidt, who was sentenced to 50 years in prison in 1998 for injecting his ex-girlfriend with HIV and the hepatitis C virus while she believed he was injecting her with vitamins, are clear examples of this.
However, scientists are careful with their assessments . Phylogenetic analysis can provide evidence that a virus found in person A is very likely to come from person B, for example, but it will never be able to prove direct transmission between the two. Therefore, the statements of the experts could mean the conviction or salvation of an individual , and at a higher level, the imposition of a sanction against a country or even the starting signal to a new war (in an accusation about biological weapons, for example), so for the moment, precaution seems to be the safest way to integrate this tool into the justice apparatus.
