Scenario: Late one rainy night, a burst of sudden screams were heard coming from the house of an elderly woman who had lived alone for about 10 years since her husband died. The next morning when her son came over to check on her as he normally does, he found her lifeless body in a pool of blood and it appeared that she had been stabbed numerous times about the head and neck area. The son immediately dialed the 911 operator to report the heinous crime.

When the Investigators arrived on the scene, they noticed that there were several foot impressions in the mud that were along the backside of the house leading up to the backdoor. As they investigated the area around the back door, they noticed what appeared to be muddy shoe prints on the floor. At this time, they called in the crime scene investigator to document and collect the impressions. When the crime scene investigator arrived at the crime scene and began to document the scene, they noticed that both the impression on the outside of the house in the mud and the footprint in mud in the back door entrance both appeared to have been made by a Nike brand shoe.

After the Crime Scene Investigator finished documenting and collecting the two items of physical evidence, they went into the bathroom that was closest to the where the body was found and they observed another partial footprint that appeared to be in blood and it bore the same type of Nike brand.

Once the house had been thoroughly checked for items of physical evidence that could probably connect a suspect with the crime scene, the Crime Scene Investigator went outside and noticed what appeared to be a tire track in the mud on the front lawn of the victims residence. They were not immediately able to say what brand that the tire might be, but they did notice that there was a lot of distinctive tread pattern present.

Could anything be done to identify the probable source of the shoe impressions and the tire impression? If so, would all shoes that were a particular brand or tires from the same manufacturer have the same patterns or could there be unique differences that can be identified that could individualize the impressions to a single source? Is there a difference between a foot impression and a footprint?

This audio will explain how impression evidence can be analyzed through a series of scientific techniques that will allow the expert analyst to determine the origin of the foot impression or the tire impression. You will learn how impression evidence is formed and the differences between two dimensional and three dimensional impressions. Through the use of the power point presentation and several sensational real cases, the forensic science techniques that are available for this type of analysis will be explored in great detail. Specific methods used in the collection of impression evidence, such as Dental stone and Electrostatic Lifting, will be illustrated. This audio will also explain how the newest technique of collection and preservation, Biofoam, is used to re-create an excellent reference sample to be compared with the forensic samples collected from the crime scene.

So go ahead and click on the appropriate box below and find out why a rock or a piece of gum on the bottom of a shoe can prove to be a very important part of individualizing the shoe impression to a specific source. Once you receive this unique information, you will always be checking the bottom of your shoe soles and looking at your tire patterns to see what makes your shoes and tires different from all the other shoes and tires everywhere. So let’s get jogging and eventually you will be driven to understand all there is to know about the benefits of Impression Evidence in helping to solve criminal cases.