Evidence Mishandling: Signs and Examples

As stated by forensic colleges, There’s no shortage of crime-fighting TV shows where protagonists brandish the latest forensic science techniques. Whether it’s DNA testing, tool mark identification, bite mark measuring, or blood spatter analysis, it’s assumed that these methods are reliable, consistent, and valid measures of criminal activity. Of course, the evidence is available for experts with trained eyes and the proper equipment, but the science isn’t without fault. Thus, it is super important that when entering a crime scene that law enforcement take all the necessary precautions to ensure there is no contamination of the physical evidence. All physical evidence should be stored in proper ways to ensure that the evidence does not deteriorate and can be easily located by a police evidence management software or tracking system.

Signs of Mishandling or Contamination

Any contamination of the crime scene or evidence is often a direct result of the law enforcement at the scene. So, the personnel must take the necessary precautions to minimize the amount of mishandling and contamination of any physical evidence present. This means personnel must enter the scene with the correct PPE (face masks, booties, head cover, gloves, and a jumpsuit). Now, if personnel answer a call and then find themselves in the middle of a crime scene, there should be an urgency to secure the scene to limit the amount of contamination that might occur. A couple of signs that a scene might have more contamination of evidence than to be expected or that evidence was mishandled should be considered at any crime scene are:

  • How long was the crime scene not secured?
  • How many people have been to the crime scene before it was secured?
  • Where is the location of the crime scene? Crime scenes located outside are harder to confidently secure than crime scenes located indoors. 
  • Was all personnel taking the necessary precautions while at the crime scene, and was everyone wearing proper PPE?

All of these questions should be at the forefront when handling any crime scene or physical evidence. 


There have been many documented cases that resulted in innocent people being prosecuted or even convicted of serious crimes based on physical evidence that was, in the end, determined to be contaminated or mishandled.

David Camm 

On September 28, 2000, David Camm discovered that his wife and two children had been killed in their home. David Camm attempted CPR on one of his sons, resulting in a reasonable amount of blood transferred to his shirt. A forensic analyst insisted that Camm’s shirt had been stained in a pattern that suggested that he was the perpetrator. This resulted in Camm being found guilty and sentenced to 195 years in prison in 2002. In 2005 new DNA was brought forward. This put a career criminal named Charles Boney at the crime scene, and the case was adjusted to where Boney committed the murders but insisted that Camm was a co-conspirator. It wasn’t until 2015 that Camm was finally acquitted and released.

Amanda Knox

On November 2, 2007, Amanda Knox returned to her apartment and found the house wholly disheveled and a good amount of blood in the bathroom. Scared for her roommate, Meredith Kercher, Knox attempted to enter Kercher’s room with no success and then called the police. Knox and another roommate, scared they had been robbed, began to rummage through their items, thoroughly contaminating the evidence. When they finally gained access to Kercher’s room, they discovered her body. Knox and her boyfriend, Sollecito, were arrested and charged with Kercher’s murder due to trace amounts of DNA evidence found on multiple items thought to be involved in the murder. During the appeals trials in 2011, many flaws were pointed out in the physical and forensic evidence. One of the significant issues included was that the police did not wear correct PPE and did not change their gloves, allowing cross-contamination. In 2015 Knox and Sollecito were exonerated.


As established, evidence mishandling can significantly impact a case and be a direct consequence in controlling a person’s fate. With so much at stake, it is wise to utilize an evidence management service to ensure all proper protocols are taking place. PMI Evidence Tracker is a powerful evidence management tool that provides Law Enforcement agencies with affordable, flexible, and easy to use systems for managing evidence and property. Contact us today to get started!