Casting in Water
Place a form around the impression, making sure the frame is large enough to come above the waterline. Be careful not to place the form so close to the impression that it risks distorting it. Remove any debris from the surface of the water. Lightly sprinkle the dental stone material over the area of the impression, about one (1) inch, allowing it to settle. Prepare a mixture of dental stone that is slightly thicker. Place the mixture into the frame by scooping. Allow 60 minutes for drying. Remove and air dry 48 hours.
Casting in Snow
Place a form around the impression. Spray “Snow Print Wax” over the impression and allow it to set up for about 10 minutes. If “Snow Print Wax” is not available, talcum powder or gray primer spray can be used, but the pouring must be done very carefully. Prepare a mixture of dental stone using very cold water. Pour the dental stone onto the impression very carefully. Cover the impression with a box and allow the cast to dry for about 60 minutes. Remove and air dry for 48 hours.
Admissibility of Footwear Evidence
“The role of the expert witness is not to determine guilt or innocence, but rather to assist the court in determining what weight is to be placed on technical evidence entered which without assistance could not be interpreted properly. “
(Cassidy, 1980)
The crime scene investigator should alway approach the crime scene as if the attorney met you at the front door and told you, “tomorrow we are going to court.” The best way to prepare for any trial is to be prepared for the unexpected.
If a thorough crime scene report is prepared, the crime scene investigator can describe the steps of the investigation chronologically. Remember, your reports and notes are subject to subpoena during a trial.
The crime scene investigator should understand the techniques and legal requirements necessary to ensure that the crime scene photographs and the evidence collected will be admissible in court.
The basic premise involved in crime scene photography is that the photographs are a true representation of the scene as it was initially observed by the investigator. Nothing will cause evidence to be tossed out of court faster by defense attorneys than no photographs of the footwear evidence prior to the crime scene investigator placing a scale in the photograph or not following proper procedures. Defense attorneys will argue that the evidence was altered.
Crime Scene Investigators are considered to be expert witnesses in the investigation of the crime scene. The expert witness is determined only by the court. The court will weigh the qualifications, experience, and demeanor of the investigator carefully every time that he/she appears. The expert witness is allowed to give an opinion on any relevant issue that is within the scope of their expertise.
Once the footwear evidence has been entered into evidence, the Footwear Examiner will take the stand to testify as to the examination or comparison procedures. Never allow yourself to become caught up in testifying to an examination or the comparison of footwear evidence unless you have been properly trained and possess the experience, qualifications and training of a footwear examiner.
References
Some of the listed books are old and out of print, but they contained important information for the writer of this article.
- Bodziak, William J., Footwear Impression Evidence, Elsevier Series, 1990.
- Bodziak, William J., US Department of Justice; FBI, Shoe and Tire Impression Evidence, September 1986.
- Cassidy, M.J., Footwear Identification, Canadian Government Printing Centre, 1980.
- Grieve, D., Journal of Forensic Identification, International Association for Identification, 1988.
- Jaroff, Leon, Reader’s Digest, “Mystery of the Iceman,” Condensed from Time, April 1993.
- Joseh, Alexander and Allison, Harrison C., Handbook of Crime Scene Investigation, Allyn and Bacon, Inc., 1980.
- Kirk, Paul, Crime Investigation, Interscience Publishers, Inc., NY 1953.
- McDonald, Peter, Tire Imprint Evicence, Elsevier Series, 1989.
- Ojena, Stephen M., Law and Order, “New Electrostatic process Recovers Visible and Invisible Dust Particles at Crime Scenes,” July 1988.
- Svensson, Arne; Wendel, Otto; and Fisher, Barry A.J., Techniques of Crime Scene Investigation, Elsevier NY, 1984.
- A paper written on Put the Suspect at the Scene of the Crime, no dates or other documentation.
- US Department of Justice, FBI Law Enforcement Bulletin, “Scientific Aides, Preserving Prints of Shoes and Tires on Hard Surfaces”, June 1961.
- US Department of Justice, FBI Law Enforcement Bulletin, “Tips on Making Casts of Shoes and Tire Prints”, October 1963.