Image from Forensic Science Service, UK.
Footprints are fairly common at crime scenes
Footwear marks are found at around 40% of crime scenes [link]. In the United Kingdom, there has been a National Footwear Intelligence and Refererence Database ustablished. They report that , Nike shoes are found most often at crimescenes there, with 60% of the shoeprints coming from this manufacturer. The most commonly encountered shoe was the Nike the Air Max 95. [link]. The bloody shoe prints at the crime scene of Nicol Simpson and Ron Goldman matched a size 12 Bruno Magli shoe, a relatively rare Italian-made model. O.J.Simpson wears size 12 shoes, which isn't that common a size. The prosecution linked O.J. Simpson to purchases of this type of shoe in order to link him to the murder scene.
"Following the murders of Nicole Brown Simpson and Ronald Goldman in the summer of 1994, photographs depicting shoeprint impressions in blood from the Brentwood, California, crime scene were delivered to the FBI Laboratory. The Los Angeles Police Department requested the determination of the brand and size of footwear that made the impressions. The impressions submitted were mainly from a path adjacent to the home of one of the victims, Nicole Brown Simpson. However, other partial impressions were on the victims' clothing.
By examining these impressions and researching the FBI reference and standards files, an FBI examiner was able to positively link some of the crime scene impressions to size 12 Bruno Magli™ Lorenzo shoes. The examiner issued a report directly to the judge in the case and was subsequently called to testify. Although the shoeprints from the crime scene could be positively linked to a particular brand and size of shoe, at the time of the criminal trial no evidence was available that defendant O. J. Simpson owned such shoes. (Bodziak 2000, pp. 431-458). [link]"
Dr. Bodziak has written a book on the topic of footware identification W.J. Bodziak, Footwear impression evidence: detection, recovery and examination (2nd ed.), CRC Press, London (2000).Between O.J. Simpson's civil and criminal trials, pictures showing O.J. Simpson in Burno Magli shoes were discovered. The existance of these shoes was evidence admitted to the civil trial, when the Mr. Bodziack restated his testimony. There were multiple pictures produced as evidence from different cameras, since it was alleged the first pictures were forged.
"William Bodziack, an FBI agent and one of the country's most foremost experts on shoe print impressions, testified that the prints were left by Bruno Magli shoes, style Lorenzo, incorporating a Silga sole with a waffle-type print. The footwear, manufactured in Italy, retailed for $160 per pair and was sold by only 40 retailers across America. In all, only 300 pairs of size 12 (Simpson's size) were ever sold. Only 9% of the population wore size 12. Simpson had denied ever owing a pair, calling them, "ugly-ass shoes."
However, on September 26th, 1993, AP photographer Harry Scull Jr. had taken pictures of Simpson wearing these exact shoes at the Rich Stadium in New York." [link]
Footprints may be found as either two dimensional prints or three dimensional impressions. Prints are made by depositing (blood, soil) or removing (dust, blood) material from a hard surface. Impressions are made in a pliable material such as mud, sand or snow. Footprints can represent both class and individual trace evidence. A shoeprint can be unique because of many variables: wear patterns can show how long it was worn and sometimes the walking pattern of the shoe's owner (pronated, pidgeon-toed). Some marks, cuts and scratches are unique to a particular shoe. Even a rock stuck in the treads of an athletic shoe can remain and leave a unique characteristic. The design of the sole is a class characteristic as is the size. However, some types of shoe are sold in limited quantities in certain sizes and markets. For shoeprints, forensic scientists lifting with electrostatic devices. Photography is the major technique used to record shoe prints and tracks. It can be enhanced with chemicals, and is often combined with casting for impressions. For additional information read the attached discussion from the Encycloperia of Forensic Science.
Tracking footprints can also be very informative
In many cases, the footprints of a suspect can be followed by a skilled tracker. There are many true and fictional accounts of individuals who are very observant who notice the trail of a fleeing individual. These are well developed skills for hunters and are taught in the military to assist in combat situations. This information was used in a trial of six men accused of smuggling drugs to indicate they were only illegal aliens who were not clearly tracked to the 250 pounds of marijuana three miles away. This was an interesting case, since the judge overruled the jury and vacated their conviction, based on the forensic evidence of the case. This is not common. [link]
The military train individuals to track footprints in combat situations.
"Displacement takes place when anything is moved from its original position. A well-defined footprint or shoe print in soft, moist ground is a good example of displacement. By studying the footprint or shoe print, the sniper determines several important facts. For example, a print left by worn footgear or by bare feet may indicate lack of proper equipment. Displacement can also result from clearing a trail by breaking or cutting through heavy vegetation with a machete. These trails are obvious to the most inexperienced sniper who is tracking. Individuals may unconsciously break more branches as they follow someone who is cutting the vegetation. Displacement indicators can also be made by persons carrying heavy loads who stop to rest; prints made by box edges can help to identify the load. When loads are set down at a rest halt or campsite, they usually crush grass and twigs. A reclining soldier also flattens the vegetation.
a. Analyzing Footprints. Footprints may indicate direction, rate of movement, number, sex, and whether the individual knows he is being tracked.
(1) If footprints are deep and the pace is long, rapid movement is apparent. Long strides and deep prints with toe prints deeper than heel prints indicate running (A Figure 8-1)
(2) Prints that are deep, short, and widely spaced, with signs of scuffing or shuffling indicate the person is carrying a heavy load (B, Figure 8-1).
(3) If the party members realize they are being followed, they may try to hide their tracks. Persons walking backward (C, Figure 8-1) have a short, irregular stride. The prints have an unnaturally deep toe, and soil is displaced in the direction of movement.
(4) To determine the sex (D, Figure 8-1), the sniper should study the size and position of the footprints. Women tend to be pigeon-toed, while men walk with their feet straight ahead or pointed slightly to the outside. Prints left by women are usually smaller and the stride is usually shorter than prints left by men. "
From Army Field Manual
No. 23-10 [link]
Footprints and stride length can be used to estimate height of the person who left them.
A related topic was featured on a recent episode of CBS's NUMB3RS where they used a mathematical formula to estimate a person's height and weight according to footprint depth.
For our lab next week, read over the two articles listed below. They are fairly technical, but at the same time they are representative of a lot of forensic science.
The development and practice of forensic podiatry
Stature and sex estimate using foot and shoe dimensions
Prelab Questions Answer the Prelab Questions based on reading the web page, the articles and the slide shows for the class this week.
Lengthy Relationships Lab Read the lab before coming to class and be ready to go! The answers to the lab are due on the next lab or earlier. They can be submitted electronically to me through WebCT or they can be printed and handed in to me in class.
Footprint Lab Group Data Summary in EXCEL Spreadsheet to use for analysis.