Persistence of Creases of the Foot and Their Value for Forensic Identification Purposes

Abstract: Foot morphology comparison is an established tool for bare and socked foot impressions left at crime scenes. This project attempts to confirm the persistence of foot creases. Volunteers' footprints were collected during a twelve-year period, and then those footprints were compared to subsequent impressions. The results lead the author to conclude that the number of foot creases varied per foot from zero to in excess of 90, averaging 15 per foot in the sample group used here. It was determined that foot creases remain persistent over time, and, when sufficient in number and significance, are a valuable tool for individualizing the donor. Barefoot impressions are rarely found at crime scenes and even more rarely are friction ridge detail and crease detail present. When an impression displays sufficient detail for creases to be noted, even if the friction ridges are insufficient for analysis, the impressions should be collected and considered for potential forensic identification based on barefoot morphology and creases of the foot.

Introduction

Friction ridges that cover the hands and feet have long been accepted as an infallible means of identification. Flexion creases of the hands and feet are anchored in the dermal layer of skin, making them permanent, but they have been less widely used as a means of identification. Most often when creases are visible, so are the friction ridges, and, therefore, the ridges are used. In the case of infants, the ridges are so delicate and fine, that, when inked, the ridges are not clear, but the flexion creases are often visible. A hospital's practice of inking the footprints of infants after birth was a means of identifying them should they be mixed up with other infants or be abducted from the hospital. Now, DNA would likely be used to establish who the parents are in the case of a mixup or an abduction, but foot creases still have a purpose for individualization.

A case requiring the examination of foot creases crossed my desk in 2002. This research project on the persistence of creases was spawned during the course of this investigation.

The Case

In January of 2002, I received a request to examine foot impressions that had been left at a murder scene in the town of Rankin Inlet in the North West Territories of Canada. Corporal Harry Harding of the Iqaluit RCMP Forensic Identification Section had attended a murder scene at a house. The victim, found lying on a bed, had extensive trauma to the head. There were bloodstains throughout the house. Corporal Harding photographed the scene and specifically the impressions of boots, socked feet, and bare feet, as well as friction ridges, both palmar and plantar, that had been left in the victim's blood.

A suspect came to light who was a friend and drinking buddy of the victim and who had legitimate and regular access to the victim's home. Corporal Harding was able to establish that the suspect's boots were of a similar pattern to the footwear impressions on the floor, but he was not able to establish a positive identification. Because Rankin Inlet is a small, remote community with limited access to outside stores, many residents wear similar footwear that is sold at the local Northern Store, the only store in town. As a result, numerous persons in this community wear the same make of winter boot. The victim's boots were eliminated as the possible source because of the wear on them.

The hand prints in blood within the house were established as belonging to the suspect (via friction ridge comparisons). At the preliminary inquiry, the suspect was committed to trial. The Crown Attorney and investigators anticipated that a possible defense strategy might be to suggest that the suspect came into the house after the murder, wearing boots, and touched his bloodied and deceased friend, thereby leaving his boot and hand marks behind. As a Forensic Identification Specialist, I was trained in foot morphology (i.e., the use of shape and contours of the foot as a means of establishing or eliminating a person as the source of a particular impression left by the foot). Consequently, the bloody socked foot and barefoot impressions were sent to me to conduct a foot morphology examination and comparison.

The ridge detail of the barefoot impressions was visible, but the characteristics were too heavily obscured by blood to do a friction ridge comparison. One of the impressions, marked as R10, had sufficient clarity to show the ridge flow, general shape of the toes and ball of the foot, and the creases in the ball and arch area (Figure 1). As part of the foot morphology protocol, inked walking barefoot impressions of the suspect had been taken for a distance of approximately 28 feet. These known impressions of the accused were compared to the bloody impression photographed as R10 by Corporal Harding, and through a combination of foot morphology and comparison of the creases, a conclusion of individualization was established: Impression R10 was made by the bare foot of the accused. Figure 2 is the inked left foot impression of the accused, and Figure 3 depicts a tracing made of the creases evident in the crime scene impression R10. The possible defense of later arrival by the suspect was also quashed, because some of the boot impressions were on top of barefoot impressions, showing that the barefoot impressions were there first.

Previous Research

The premise that nature does not repeat itself is the basis for forensic identification. We accept that each person's features have their own unique configuration. Research has been done in relation to friction ridges, ear prints, and footprints [1- 4]. In anticipation of the court case, a review of the literature turned up no previous cases in which foot creases had been used for identification. In the area of research, few studies have been done, and most are in relation to infants and do not consider persistence.

In 1959, Blake [5] researched the individualizing power of foot creases, utilizing the footprints of 1,388 infants. He concluded that "the creases are individual to each foot and no two feet are alike and they remain constant after birth" [5]. No indication was given as to how long these infants were followed to establish the persistence of the creases.

In work done in 1979, Taylor [6] stated that creases should only be used as an alternative to friction ridge identification, because he claimed to have found similar crease structure in two different infants. However, the creases on the footprints shown in his article do not seem similar in shape.

Bali's Anthropology of Crease Morphogenesis: A Scientific Analysis [7] deals specifically with crease morphology and has a chapter on foot creases; however, the author focuses on the classification of the creases on the basis of shape and location on the foot, as opposed to the permanence and individualizing power of them.

Lohnes [8] refers to Blake's research in a 1986 article in which he states, "Flexure creases are unique and remain constant during the first few weeks of life. They do not change in direction or distance from each other. As a child continues to grow, there is a gradual change in size, shape and quantity of flexure creases."

Kimura et al. [9] studied 160 fetuses from 6 to 20 weeks' gestation. Their research showed that some creases develop at the same time as volar pad development, and that, with only some exceptions, creases seem to develop independently of the flexion movements of the hand and foot. A further study by Kimura et al. [10] led them to conclude that "once these creases have developed they never disappear even though the pads regress". They also established that most creases appear by 13 weeks' gestation, somewhat earlier than epidermal ridges.

Qamra et al. [11] conducted a study of the footprints of 725 adults. In this study they primarily examined foot morphology, but they commented that "crease marks are caused by skin folds, some permanent, others not" and indicated that both types were useful evidence to identify individuals because they "differ from person to person in size, shape and position". They also observed that creases tend to originate in the instep and run toward the toes and outer margins of the foot and are more prevalent in flatfooted persons and in women more so than men.

Palm impressions have been studied previously. Three major creases (thenar, proximal transverse, and distal transverse) have been named. A second group of palmar creases (known as minor flexion creases) has also been identified: longitudinal, accessory distal, "E" lines, and hypothenar. A third and final grouping of creases (secondary creases) includes all remaining palmar creases not classified as major or minor palmar creases. Ashbaugh states, "Palmar flexion crease identification has the potential to parallel friction ridge identification on evidential value." [12] The same can be said for the flexion creases of the foot. Because creases of the foot also develop prior to and during the early stages of friction ridge formation, they are part of the substructure of the skin and are, therefore, permanent.

Unlike palms, however, creases of the feet do not have established nomenclature. There are, in fact, no creases that appear in all footprints, some footprints that show no creases at all, and other footprints that have many creases. Considering that skin structure, friction ridge growth, and crease development are identical in both palmar and plantar surfaces, research that confirms the uniqueness and persistence of flexion creases of the palmar surfaces, like that conducted by Ashbaugh [12], can be applied to the flexion creases of the foot as well.

Methods

The current project was carried out in preparation for court to show that the creases of the foot are unique to an individual, and that they are persistent, the two basic tenets of individualization.

Inked footprint impressions were collected from 50 volunteers who had previously volunteered their footprints to the foot morphology database for Kennedy's research [4]. Each set of footprints was taken using an inkless pad and specially formulated paper that records the foot impression, including friction ridge and crease detail. The foot morphology of the earliest set of footprints for each subject, including the creases, was traced. The total number of creases was also noted for each footprint. Subsequent sets of footprints taken from each subject were then compared to the initial set. The time that elapsed between sets of footprints varied from 1 to 12 years. Some subjects had one set of subsequent footprints, while others had numerous sets available for comparison. Each set of footprints available for each individual was compared to the earliest available set. Notes were made as to consistency in the creases in subsequent sets of footprints and the number of new creases that could be observed, as well as any changes noted. A total of 137 sets of footprints were compared.

Results

For all individuals in this sample, creases were consistent during the years that the subject submitted footprints for comparison. Note that the time that elapsed between Figures 4 and 5 is seven years, and between Figures 6 and 7 is six years. New creases sometimes were evident in later sets of footprints, but most often they appeared as extensions of creases that were previously there. Periodically, a crease or creases would be absent in a subsequent set of footprints, but would then reappear in an even later set (Figures 8, 9, and 10). This may be explained by the exhaustion or freshness of the inkless pad being used, or conversely, that some creases were in fact white lines (i.e., nonpermanent creases, caused by a buckling of dry skin, fissures, or temporary cracking of the skin, which do not have a permanent origin in the dermal layer of the skin). This fact emphasizes that creases need to be examined in concert with other creases and other features, such as morphology and friction ridges. Sometimes the impression was too faint and creases could not be seen, and sometimes heavy ink obliterated all ridge and crease detail.

The number of creases in this sample collection varied from zero to more than 90 creases per foot, with the average being 15 per foot. Figure 11 shows an impression with few creases, and Figure 12 shows an impression with an extremely large number of creases. Creases occurred primarily in the instep (in the area behind the ball of the foot and the inner arch). Some toe creases were noted, though they were not common in this sample group (Figure 13). Creases, or more aptly white lines, may increase with age, but they are not necessarily a function of age. For example, the youngest research subject (the author's seven-year-old daughter) has more creases than many other subjects.

During the course of this research project, footprint impressions were collected from a set of self-reported identical twins. The morphological shape of their feet had similarities. Overall length, ball, arch, heel width, and toe pad locations of some of the toes were similar. When thoroughly compared, the morphology differentiated one from the other, and their creases were also distinctly different.

Conclusions

Although the use of foot creases for individualization may rarely be required, if it is present, foot creases should be analyzed, compared, and used along with all of the other features that are available (e.g., foot morphology and friction ridge structure) to assist in establishing or eliminating potential sources. This preliminary study indicates that foot creases are unique in configuration and are persistent over time. Research that has been conducted on palmar flexion creases should be just as applicable to creases of the foot.

In the case described above, the accused plead guilty after the report was received, prior to trial [13].

Acknowledgments

The author wishes to thank all of the volunteers who donated their footprints for this project, many of whom are RCMP Forensic Identification Specialists from across Canada. Thanks also to Corporal Harry Harding for background on the case, photography of the impressions, and permission to use his case for this paper. Sergeant Robert B. Kennedy (RCMP Forensic Identification Research Services in Ottawa) provided encouragement to initiate this project; provided assistance by locating and supplying the initial footprints out of his database, as well as locating some of the previous research articles; and provided guidance in reviewing this article. Without his generous support, this project would not have been possible. Thanks also to Brian Yamashita for his careful proofreading and suggestions that were provided in the final review of this paper.

For further information, please contact:


Shelly L. Massey
Forensic Identification Section
Red Deer RCMP
4300-55 Street
Red Deer, Alberta T4N 2H1
Canada
shelly.massey@rcmp-grc.gc.ca

References

1. Cummins, H. The Topographic History of the Volar Pads (Walking Pads; Tastballen) in the Human Embryo. Contr. Embryol. Carnegie Institution of Washington: Washington, DC, 1929, 20, 105-126.
   
   
2. Hale, A. R. Morphogenesis of Volar Skin in the Human Fetus. Am. J. of Anat. 1952, 91 (1), 147-173.
   
   
3. Van Der Lugt, C. Ear Print Identification; Elsevier: Netherlands, 2001.
   
   
4. Kennedy, R. B. Bare Footprint Marks. In Encyclopedia of Forensic Sciences; Siegel, J. A.; Sauklko, P. J.; Knupfer, G. C., Eds.; Academic Press: New York, 2000; Vol. 3, pp 1189-1195.
   
   
5. Blake, J. W. Identification of the New Born by Flexure Creases. Ident. News 1959, 9 (9), 3-5.
   
   
6. Taylor, R. A. Flexure Creases Alternative Method for Infant Footprint Identification. Ident. News 1979, 29 (9), 12-14.
   
   
7. Bali, R. S. Anthropology of Crease Morphogenesis: A Scientific Analysis; Concept Publishing Company: New Delhi, India, 1994.
   
   
8. Lohnes, R. C. Infant Footprint Identification by Flexure Creases. Ident. News 1986, 36 (8), 10-13.
   
   
9. Kimura, S.; Kitagawa, T. Embryological Development of Human Palmar, Plantar and Digital Flexion Creases. Anat. Rec. 1986, 1 (216), 191-197.
   
   
10. Kimura, S.; Schaumann, B. A.; Plato, C. C.; Kitagawa, T. Developmental Aspects of Human Palmar, Plantar, and Digital Flexion Creases. In Trends in Dermatoglyphic Research; Durham, N. M.; Plato, C. C., Eds.; Kluwer Academic Publishers: Boston, MA, 1990.
    
    
11. Qamra, S. R.; Sharma, B. R.; Kaila, P. Naked Foot Marks: A Preliminary Study of Identification Factors. For. Sci. Int. 1980, 16 (2), 145-152.
    
    
12. Ashbaugh, D. Quantitative-Qualitative Friction Ridge Analysis; CRC Press: Boca Raton, FL, 1999.
    
    
13. R. vs Yvo Airut Jr. Manslaughter Conviction registered in Nunavut Court of Justice, Rankin Inlet, Nunavut Territory, Canada. April 23, 2002 (Offense occurred on December 19, 2000.)

Figure 1
Crime scene impression.

Figure 2
Suspect's inked left foot impression.

Figure 3
Tracing of the creases of the crime scene impression.

Figure 4
Initial sample of a footprint studied.

Figure 5
Same subject as in Figure 4, showing creases 7 years later.

Figure 6
Initial sample of a footprint studied.

Figure 7
Same subject as in Figure 6, showing creases 6 years later.

Figure 8
Initial sample of a footprint studied. Taken November 2000.
(Note crease.)

Figure 9
Same subject as in Figure 8. Taken February 2002.
(Crease appears to be missing.)

Figure 10
Same subject as in Figures 8 and 9. Taken February 2004.
(Note crease is again present.)

Figure 11
Example of foot with very few creases.

Figure 12
Example of a foot with more than ninety creases.

Figure 13
Toe creases.

*From the Journal of Forensic Identification Vol. 54, No. 3, May/June 2004
The Official Publication of the International Association for Identification
"Reproduction of the Journal of Forensic Identification, in whole or in part, for noncommercial, educational use is permitted provided proper citation of the source is noted. Reproduction for any other use is prohibited without prior written permission. Requests for permission may be addressed to the editor (of the Journal of Forensic Identification -- jfieditor@theiai.org)."

Article posted: May 7, 2010