Over ninety-nine percent of crimes in the United States are committed in shoes with synthetic soles. Identifying the shoe based on the impression it leaves behind is a forensic problem that William Bodziak has specialized in since joining the FBI in 1973. During his 24-year career at the bureau, he helped organize the FBI's vast database of shoe soles. Author of Footwear Impression Evidence: Detection, Recovery, and Examination, he is now retired from the FBI and is a consultant based in Florida. A barefoot Sina Najafi and Frances Richard spoke to him on the phone.
Perhaps the most famous case at which you testified was the O. J. Simpson trial. How did you become involved in that?
The LAPD asked us to help because they had the shoe prints on the bloody walkway but they couldn't come up with the type of shoe or the size. We searched our database at the FBI and we didn't find it either, because it wasn't an athletic shoe design and most of our database designs are athletic shoes. I examined the shoe design on the walkway and it had a pointed toe and a raised heel. There were a couple of other design features that made me think that it was a casual but expensive Italian shoe. That was just a guess and I was lucky. I looked at my resource material and I identified about 80 importers and manufacturers of high-end Italian shoes. We actually prepared a fax with pictures from the crime scene and sent it to these 80 importers and manufacturers . Two days later I got a call from the owner of Bruno Magli in North America. He said they had made the upper part and the bottom, and that it was a Bruno Magli design. There were only ten molds used to produce the soles for all sizes, and each mold was a little different, so it was very easy to say it was a size 12. The total number of those shoes sold in the U.S. in size 12 was 299. The shoes sold for 160 dollars. The investigators checked Simpson's credit cards and the 40 stores that sold this shoe. We did find that he bought a lot of size 12 shoes at Bloomingdale's but they couldn't remember what design the shoes were and he buys almost everything with cash. After the criminal trial, we found that there were a couple of AP photographers who had taken some pictures on the football field back in September of 1993, eight months before the crime, of Simpson walking across the end-zone and you could actually see the shoe including part of the bottom. One of these photographers lightened the picture up and he went to the National Enquirer who published it. So we had the photographer bring his negative to the laboratory. Once this became public other people who had taken pictures of him at the game also produced pictures of Simpson in the shoes. We were able to lighten them up again digitally as well as photographically to show that they were in fact the Bruno Maglis.
How sophisticated was the field of sneaker forensics when you arrived at the FBI?
There were six examiners at the FBI who were quite experienced and they all contributed to my training. Common sense and logic will tell you that even when there were cavemen, they were following tracks of some type and were probably not only following animals but maybe other people. Obviously we're more interested in shoes but the origin of people laying down some form of evidence as they walk is something that is quite old. I'm not a historian but there are references to footwear impression testimonies dating back to the 1800s. Certainly, in US courts you will find a lot of cases from the early 1900s to the present.
But there was really a void in the education of examiners about the evidence. In 1983 and 1984, I organized and hosted the first technical conference on footwear and tire impression evidence and in 1985 I created the first formal class that was ever taught on footwear impression evidence at the FBI Academy.
How does the work of shoe impression identification break down?
First, you have the problem of understanding how impressions are deposited by shoes, and how to find them. Once you find them there are different ways to recover the evidence. If someone steps on a piece of paper you can pick it up and take it to the laboratory, but most of the time you've got a bloody impression on a tile floor that you can't carry back to the lab. So you have to photograph the evidence properly. It has to be done with scale in a prescribed way.
There is casting, which is filling in impressions that are in soil or sand or snow with a dental stone material that's like plaster of Paris. And then there are ways of lifting impressions, which means transferring a two-dimensional impression to an object like a black lifting film or gelatin film or adhesives that you can actually pick up and carry back to the lab. You normally never get a complete lift but there are a number of different methods, both electrostatic and conventional. You have to make a decision depending on where the impressions are, and that includes consideration of chemical enhancement of bloody and non-bloody prints.
How does chemical enhancement work?
It's a way of improving the visualization of the impression. For instance, a crime such as multiple stabbing, you get quite a lot of blood. The person who is doing it is picking up blood on his shoes but the amount of blood in the heavier blood-soaked shoe prints prevents you from seeing the finer detail in the shoe. So as the person continues to walk, whether it's on carpeting or tile or floor, the prints get lighter. You're looking at the carpet or the floor and you don't see those lighter prints, but if you spray certain chemicals, then you can enhance those prints and the lighter ones actually have more detail. There are about 20 different chemicals to enhance blood. Some of these will turn the blood red, some blue, some purple; some of them, like Luminol, make the impression glow in the dark.
What are you looking for once you've got the impression and you're beginning to read it?
Athletic or synthetic soled shoes account for probably 99.9 % of crimes—I can count on one hand the number of leather shoes or cowboy boots I've encountered in 29 years. When we do the comparison, we don't look at an impression and say, "Oh, there are nine rows of herringbone on a particular Adidas model, and that means it's a size eight." What we're doing during the examination is comparing it with the suspects' shoes. We will make test impressions of the suspects' shoes and compare the specific size and design features. That part is pretty cut-and-dried. What would it mean if the size and design matched? It does not mean that that person's shoe caused the impression because thousands of other shoes could have done the same, but it is very important evidence. There are 1.5 billion shoes sold each year in this country with thousands of designs and many sizes of each. So if you were to walk out in the street and try to find another pair of shoes in that same design you might spend the rest of your life and never find it. But as the shoe wears, the design begins to change.
Is it possible ever to get conclusively down to one pair?
Not based on design and wear alone. Wear characteristics are very good in reducing the possible number of shoes that could have made it. Some people have unusual wear patterns on their shoes that are retained in the impression very clearly. In a case like that, you find yourself thinking, "I know these are the shoes but as a scientist I can't say this absolutely." But the next part of the exam, the final part, is the individual characteristics. Let's say you walk around in one pair of shoes for a couple of months. You look at the bottom of your shoes and you find there are a few cuts and scratches on them. They probably got there because you stepped on a sharp rock or some glass. No other shoe of that size and design from that mold is going to have those marks because they occurred totally randomly. If these types of characteristics are present, then the shoes can be positively identified as the ones that made the crime scene impression.
If it were up to the FBI, they would probably like to have an individual number on the bottom of every shoe.
That's been jokingly suggested before for shoes and tires—like your social security number. Obviously this is not possible, nor practical.
So if someone were to commit a crime, they should do so in a brand new pair of shoes?
That's not a bad idea! That would minimize the exam that could be done and, in fact, we used to joke about bank robbers because they often seemed to have newer shoes. For some reason bank robbers love to jump up on the bank counter. They get up there and brandish their guns. It's a place where they feel like they can control everyone and see everyone. I have testified many times to positive identifications of a person's shoes up on a bank counter when they were wearing a full Halloween mask and gloves. They left no fingerprints, no way to identify them in a lineup but the only thing that allowed us to place them in that bank is the identification of their shoes on the counter. I had one case in Washington where the guy returned to court after my testimony without his shoes on, saying he wasn't wearing them anymore. He was so upset by the evidence.
They should have a thin layer of Plasticine on the bank counters everywhere.
Well, banks love to wax the counters every night with Lemon Pledge or that kind of stuff, and you can take a perfectly clean pair of shoes and walk down a bank counter and leave the most beautiful impressions you've ever seen. What we do is to either develop the impressions with a variety of fingerprint powders, or if the shoes had picked up dry dust from the floor of the bank, we can pick the impression up electrostatically. Every bank has some kind of camera. The first thing we do is take the tape out of the camera and look to see where the bank robbers walked. We then use special lighting and other techniques to find those impressions.
What if I wanted to do a crime and I wore my sister's shoes?
We've had a couple cases where that was alleged. There's actually an examination where you can take a person's foot and compare it to the inside of the shoe where people leave their barefoot impression. If you look in your shoe, sometimes you can see a toe pattern but the shoe must be worn for a while for that to occur. If you wore your sister's shoes, went down to the local store and robbed it, went back and gave her shoes back and she didn't know it, we would only find your sister's footprint in the shoe. You'd think DNA would be great inside shoes but what happens is there are also a million sloughed-off skin cells that people leave on the ground, and when you walk around in socks and then you put on your shoes you are making deposits in your shoe. It's like a bank; you keep depositing these cells and they're not just yours.
How did the FBI database of shoe soles develop?
The database at the FBI has actually been around since 1935. They used to have pictures of heels and soles in a file cabinet. Back then, all the manufactures were in this country and they sent anything to the FBI that the agency wanted. Of course then, there weren't so many athletic shoes. There was Pro-Ked, Converse, Chuck Taylor, Uniroyal, Goodyear—some of the rubber companies had their own shoes and they were all gum rubber athletic shoes of very poor quality by today's standards. It was not until the late 1950s and early 1960s that specialty athletic shoes started being produced. The FBI shoe database was first computerized in the early 1980s on a mainframe, and we then redid it on a PC in 1991. I managed the database for about 12 years.
How do you get all the sneakers? Do you receive new models from Nike as they come off the line?
We have about 80 manufacturers or importers that put out catalogues depicting the bottoms of their shoes, including of course Nike and Reebok. These catalogs come out before the shoes do, so hopefully by the time the shoes are on the market they are in the database. There are also an awful large number of shoes that are imports from a variety of countries like China where they may make 50,000 pairs in total and then ship them over. They are virtually impossible to trace.
How many shoes do you have in the database?
When I left, it was several thousand. We were very adamant about putting each design in only once. So if Nike made a shoe in 1999, and they decided to make that same design again in 2000, we would not put that design in twice, but just reference it to the 2000 catalogue.
Have you ever worked on a case where the crime took place in a shoe store itself?
Actually, yes. There was theft of a large quantity of shoes from a shoe store and it was burglarized during the night. The robber pulled his truck up and went into the shoe store and the first thing he did was to take his old shoes off and put on a new pair. We actually compared his feet with the impressions in the shoes he'd left behind. If he had just taken his old shoes with him, I don't know if any other evidence would have linked him to the crime.
Do you ever profile the person based on thinking that a certain kind of person buys a certain kind of shoe?
I am told that there are still certain gangs that wear certain types of shoes, but the local police usually know that. In the laboratory, we are only interested in the comparison of the shoe with the crime scene impression.
Are there any shoes that are over represented in crime?
No, I don't think there is any correlation at all.
You also specialize in tire impressions and in fact testified in the Oklahoma bombing case about some tire impressions left by McVeigh's Ryder truck. How close are shoe impressions and tire impressions?
The examination of tires is different in some respects. Most passenger tires have a series of design elements that go around the tire. If you look at them closely you see that their size changes. If you get a tire impression at a crime scene you should be able to to find that spot on the tire that potentially made the track, and then you can be much more exacting with comparing the wear and individual features. Tires are a much more complicated piece of engineering than a shoe but the comparison and recovery of the evidence is the same.
When you go into a shoe store and are looking around at shoes, do you tell people that you are from the FBI?
No, I act as if I am just looking. I actually took a footwear class of 20 people to a shoe store one night and we went in and there was only one salesman. We are all pulling out shoeboxes, but nobody bought anything. I don't know if he knew what hit him. We finally explained to him who we were. I still go into shoe stores a lot.
William Bodziak is a former agent with the FBI and the author of Footwear Impression Evidence: Detection, Recovery, and Examination (CRC Press, second edition).
Sina Najafi is editor-in-chief of Cabinet magazine.
Frances Richard is a poet living in New York. She is the non-fiction editor of Fence magazine and an editor at Cabinet.
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