The Usefulness of DNA Evidence in Criminal Investigations

Many people believe that if a criminal is not caught immediately, the DNA evidence collected at the scene is useless. This assumption is based on the misunderstanding that a comprehensive DNA database of all individuals' profiles exists. However, as technology and the nature of criminal investigations evolve, the use of DNA evidence remains a powerful tool in ensuring justice. This article will explore how DNA evidence continues to be valuable, even if the suspect is not initially apprehended.

Understanding DNA and Genealogical Databases

DNA, once collected and analyzed, can be cross-referenced with genetic databases free of charge. One of the most widely used platforms for genetic genealogy is Gedmatch. This database, which is also employed in finding birth families and biological relatives of individuals in adoption, can invaluable for crime solvers. Since many individuals, especially those in affluent societies, have contributed their DNA to these platforms, it is highly probable that relatives of the criminal have also uploaded their profiles.

The Power of Genetic Ancestry in Identifying Offenders

Once genetic profiles are uploaded to Gedmatch, detectives can employ standard genealogical techniques to identify common ancestors between the subject and the matches found in the database. By tracing the descendants of these common ancestors, investigators can narrow down potential suspects based on geographical location, age, and other critical details. At this stage, a DNA sample can be obtained from the suspect to confirm their identity and match it with the evidence found at the crime scene.

Expansion of DNA Databases and Law Enforcement

Law enforcement agencies are constantly expanding their DNA databases. The Federal Bureau of Investigation (FBI) maintains the CODIS (Combined DNA Index System) that is continually updated with samples from individuals who have been arrested and detained. Interestingly, while joining the military triggers the submission of fingerprints to the FBI database, DNA samples are not typically collected. This oversight highlights the need for a more comprehensive approach to DNA collection.

Collecting DNA Evidence

Beyond arrestees, DNA can be collected from individuals based on warrants or even environmental samples. For instance, if a suspect's DNA is found on a discarded soda can, law enforcement can request aDNA sample. This practice ensures that the database remains relevant and up-to-date. If a suspect's DNA is not initially present in the database, it may be collected later through investigative efforts or luck. This means that even if a DNA profile isn't in the database at the time of a crime, it can still be added and used to solve the case or aid in a court trial.

Potential for Future Capture

Criminals might not be caught immediately, but they could still be apprehended later through other evidence. DNA profiles in genetic databases can also be updated as individuals are arrested or serve jail time, further enhancing the potential for identifying and convicting them. In cases where a suspect isn't exonerated through DNA evidence immediately, the data can still be used to exonerate them in the future. Additionally, the DNA of a relative could be already in the database, leading investigators to the culprit.

Conclusion

Therefore, DNA evidence is not useless simply because a criminal is not caught immediately. It can be a crucial tool in solving crimes and bringing criminals to justice, even years after the crime occurred. The use of genealogical databases and ongoing efforts to expand DNA databases ensure that potential matches are constantly being evaluated. This approach not only enhances the efficiency of law enforcement but also increases the likelihood of achieving justice.