Evidentiary Value of DNA Evidence

In the early years of DNA testing, the testing provided some narrowing of suspects, but often yielded erroneous results. Courts concerned with the reliability of DNA evidence often excluded it. In the last ten years, however, DNA technology has significantly advanced to more discriminating methods. The introduction of DNA profiling has revolutionized forensic science and the criminal justice system by providing courts a means of identifying . . . perpetrators with a high degree of confidence.  Modern-day DNA evidence as such is much more capable of definitively excluding potential suspects and exonerating wrongfully convicted defendants. But before the evidence can play this significant role in assuring a fundamentally fair criminal justice system, it must be admissible. 

The most strongly contested DNA admissibility hearing held to date occurred in United States v. Yee, 134 F.R.D. 161 (N.D. Ohio 1991.  The victim in “Yee” was shot 14 times at close range in his own van.  He was apparently mistaken by his assailants as the leader of a rival gang.  Blood enzyme tests on blood stains recovered from the van revealed that some of the blood was not consistent with that of the victim’s, leading investigators to theorize that one or more of the rounds fired into the van miscarried, hitting one of the attackers. 

A DNA profile analysis performed by the FBI Laboratory comparing the blood recovered from the van and that of one of the defendant’s resulted in a match.  Accordingly, magistrate recommended that FBI’s DNA test results be admitted.  The magistrate based his decision on the requirements of the “Frye” standard, finding that there is “general acceptance in the pertinent scientific community that the procedures developed and implemented by the F.B.I. for determining that the DNA patterns from a known [i.e., a criminal suspect] source match with DNA patterns from a `questioned’ [i.e., crime scene] source are reliable.” 

The U.S. District Court for the Northern District of Ohio subsequently adopted the magistrate’s recommendation, recognizing the reliability of the evidence.  After that several States have also recognized the inherent reliability and probative value of forensic DNA evidence and have passed statutes deeming it admissible in criminal prosecutions.


Inside Evidentiary Value of DNA Evidence