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Forensic DNA testing charges “John Doe”


In many states, sexual assault crimes are subject to statutes of limitation, which set the timeframe within which an offender can be charged with a crime. Depending on the state in which an assault occurs, statutes of limitation for a sexual assault crime vary greatly.

However, prosecutors in some states such as California, Washington and Ohio have been able to circumvent statutes of limitation, in some cases involving newly-discovered DNA evidence that could lead to the identification of a suspect. By using DNA found on evidence at a crime scene, prosecutors can elude the state’s statute of limitations and consequently bring charges against an unidentified person, essentially charging a DNA profile with a crime until the individual who matches that profile can be located. In other words, if DNA evidence is found at a crime scene even years after the crime was committed, prosecutors in some states can charge an unidentified suspect, or “John Doe”, for the crime that the forensic DNA testing links them to. Wisconsin was the first state to uphold an arrest warrant for an unidentified suspect in October 2000 with the use of forensic identity testing. The idea behind charging an unknown suspect based on his or her DNA profile is to keep statues of limitation from expiring, which would prevent offenders from escaping charges because law enforcement personnel could not identify them within the timeframe set by the statute.

In these DNA-based “John Doe” cases, the forensic laboratory has already run the DNA profile obtained from crime scene evidence through CODIS and determined that there aren’t any matches to known criminals. Asking the courts to approve an arrest warrant for an unknown person to whom the DNA profile in question belongs is considered a last resort. However, with thousands of profiles being added monthly to the national DNA database and crime labs periodically running DNA profiles, the chance of a future CODIS hit on an unsolved “John Doe” case is likely to occur.

Defense attorneys have concerns about charging unidentified individuals with crimes without a time limit within which law enforcement are required to close the case. One concern is that as time passes, it may become more difficult to defend an alleged offender against state claims of evidence. Additionally, defense attorneys may not be able to find reliable witnesses who could testify on behalf of their client if they are tried for a crime many years after it took place. Depending on the number of years that have passed since the crime, potential witnesses for the defense could be deceased, ill, incarcerated or may simply have forgotten many details about the crime. In addition, there are technology and evidence preservation concerns with these types of cases. As time passes forensic DNA testing will likely become more efficient and testing procedures and equipment used today may not integrate with future technology. As a result, DNA evidence preserved using current standards could prevent future DNA analysis with the use of upgraded technology.

Criminal statutes of limitation are not mandatory or required by federal law. State legislatures may change or even eliminate a statue at any time as long as constitutional guidelines are followed. In 2003, the U.S. Supreme Court ruled that a state may not retroactively extend statues of limitations in criminal cases, but if a state wants to change a particular statute for future cases, that is within constitutional rights. For example, a state may change the statute of limitations on rape cases by increasing the amount of time lawmakers have to charge a suspect in a crime, but the state cannot retroactively add years of investigative time to a rape case that may still be unsolved but for which the statute of limitation has expired.

While very new and still rare, all existing “John Doe” cases involving forensic DNA testing have been upheld in each of the state supreme courts that have considered them.

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