Abstract This paper provides an overview of the use of DNA in criminal investigations. It shows how DNA can be helpful and harmful in terms of validating a narrative, how it has been used to exonerate inmates and used to wrongfully convict others. It shows how juries view it as 95% accurate while Israeli scientists show that DNA evidence can be manufactured simply by scientists obtaining access to a DNA profile. It discusses the role that states play in allowing for DNA usage in criminal cases, and it examines how criminal investigators must be concerned about ethical issues when using DNA profiling in their investigation. It concludes that DNA usage in criminal investigation should neither be wholly accepted as flawless nor wholly rejected as useless. Every piece of evidence matters, and with DNA evidence it is no less—the way it is handled and understood is what matters most.

Keywords: DNA evidence, DNA testing, DNA criminal justice, DNA criminal investigation

Introduction

The use of DNA evidence in criminal investigations is still somewhat controversial even though the technology exists for this tool of crime scene analysis to be utilized in every relevant case. Part of the reason it is controversial is that it could, if applied across the board, be used to overturn hundreds of cases in which DNA evidence was not permitted at trial and which could exonerate the defendant, as in the case of Bruce Godschalk, who was convicted of rape in 1986. Years later, DNA evidence was used to exonerate: DNA testing proved that Godschalk was not the rapist (Krieger, 2011). On the other hand, DNA evidence is viewed with a great deal of suspicion by those who simply do not trust the process or the notion that DNA evidence is protected in a chain of custody. For example, Austin (2015) notes that “scientists in Israel have demonstrated that it is possible to fabricate DNA evidence, undermining the credibility of what has been considered the gold standard of proof in criminal cases.” So while DNA evidence can be used to help defendants, it can also be used to frame them: Worth (2018) states, for instance, that “we leave traces of our genetic material everywhere, even on things we’ve never touched. That got Lukis Anderson charged with a brutal crime he didn’t commit.” As The Marshall Project points out, secondary transfer of DNA made it appear that Anderson, a homeless person, was guilty of killing an elderly person he had never met. As DNA is a complex matter that still requires understanding from a scientific point of view, this paper will discuss the positive and negative aspects of using DNA in criminal...

Today, criminal investigators have a number of tools at their disposal to help solve crimes. These tools include the use of psychological profiling, geographical profiling, victim profiling, and DNA profiling. DNA acts not only as physical evidence that can potentially verify an account of what happened at a crime scene, it also can act as a source of information for profiling. A DNA database is essentially like a fingerprint database and contains information that can link suspects to specific crimes while exonerating others. For example, in a rape case, if DNA is collected at the scene, it could match a set of DNA in a profile and bring up the name of a suspect which could be used by criminal investigators to make a case.
DNA use can help to set the record straight. For innocent persons convicted of a crime they did not commit, DNA evidence has been used to exonerate them. Many more await the opportunity to avail themselves of DNA testing to prove they were not at the scene of the crime (Krieger, 2011). In cases where it is difficult to determine whether or not a suspect was at the scene of a crime, DNA usage can be instrumental in making the case.

Worth (2018) states that “DNA is the most accurate forensic science we have. It has exonerated scores of people convicted based on more flawed disciplines like hair or bite-mark analysis. And there have been few publicized cases of DNA mistakenly implicating someone in a crime.” Does this mean that DNA usage is always and in every case 100% accurate? Not at all—it is simply one more tool that criminal investigators can rely upon to help make a case. It should never be used to tell the whole story, just like no case should depend solely upon the use of one, single witness. For that reason, and “like most human enterprises, DNA analysis is not perfect. And without study, the scope and impact of that imperfection is difficult to assess, says Peter Gill, a British forensic researcher” (Worth, 2018).

Why DNA Use is Problematic

As evidence, DNA is not above being tampered with—yet juries respect DNA evidence almost completely: Lieberman, Carrell, Miethe and Krauss (2008) showed that jurors tend to view DNA evidence as being 95% accurate and indicative a person’s guilt or innocence. This is problematic because DNA is simply not that conclusive. As stated above, it can be helpful—but it is not to be relied upon as a the ultimate arbiter. The case of Lukis Anderson shows as…