Shoeprints are among the most revealing forensic evidence. They may not stand in the spotlight like fingerprints or DNA, yet they’re just as crucial, and often among the first evidence collected. This article explores forensic shoeprint analysis using Amped FIVE, emphasizing photographic documentation, image enhancement, and accurate scaling to support clear forensic and courtroom evaluations.
“There is no branch of detective science which is so important and so much neglected as the art of tracing footsteps.”
– Sherlock Holmes, A Study in Scarlet (Arthur Conan Doyle)
With these words, Sherlock Holmes reminds us of something that remains just as true today as it was in the foggy streets of Victorian London: footwear impressions are among the most revealing forms of forensic evidence.
And so, it comes as no surprise that in A Study in Scarlet, Holmes does not rush headlong into 3 Lauriston Gardens to unravel the mystery of Enoch Drebber’s death. Instead, he takes his time – carefully examining the footpath in front of the house and the muddy garden paths – before ever setting foot inside.
Holmes knew: the ground beneath our feet can speak volumes, if only we take the time to look.
In modern forensic science, shoeprints serve a dual function:
- They are not only capable of helping identify a suspect, for instance through distinctive wear patterns or damage on the sole that can be directly matched to shoes found in a suspect’s possession – they are also situational traces.
- They provide insight into how a perpetrator moved through a crime scene, which routes they took to approach and leave, and where critical moments may have taken place.
As one of our crime scene instructor used to say:
“No suspect flies through the crime scene.”
A useful reminder that every step matters. Unless, of course, the suspect moves like Ethan Hunt in Mission: Impossible, descending silently from the ceiling without leaving a trace.
In this article, we’ll explore how forensic image processing using Amped FIVE supports photographic documentation and digital enhancement of footwear impressions.
The Importance of Context: Overview and Detail Photography
Before we dive into the digital forensic processing of footwear impressions, we begin, as always, with the photographic documentation of the trace.
This includes close-up detail images of the shoeprint itself and overview photographs that clearly show the position and orientation of the print within the scene.
These overview images are essential for preserving the contextual information that defines a shoeprint as a situational trace.
Alright, let’s take a look at our first example.
Here, we see an overview image of the interior of a vehicle. A partial shoeprint is visible on the inner door panel.
Using the Annotate filter from the Presentation filter group, image labels and visual markers can be added quickly and efficiently.
Important areas can be further emphasized using the Magnify tool, allowing for focused visual attention where needed.
If the text is not meant to appear directly within the image, the text box can easily be dragged outside the image area. It can be placed below the image, for example.
Amped FIVE will automatically extend the canvas to accommodate the new layout.
In the Options section of the Annotate filter settings panel, you can enable “Extend Canvas” and “Auto-pad Extended Canvas” to fill the expanded area with a background color of your choice.
Now it’s time to take a close-up photograph of our partial shoeprint.
In the article on processing fingerprints in Amped FIVE, we discussed the three cardinal rules of forensic photography. One of these rules states that traces should always be photographed in a planar (parallel) orientation. This is intended to maximize depth of field and minimize perspective distortion.
However, in practice, we often find traces such as fingerprints or footwear impressions most clearly visible under oblique lighting. In our current case – with the partial shoeprint on the inner door panel – this is exactly what we observe.
In the overview image, we are not looking straight at the trace, but rather from a slightly elevated, oblique angle, which allows the impression to stand out clearly from the dark plastic of the panel.
The trace suddenly becomes much less visible when we move the camera into a planar, straight-on position to take a proper detail shot.
In this case, the main reason for the loss of visibility is the slightly reflective surface of the interior door panel.
One way to address this is by adjusting the lighting setup. We can use an external flash to make the footwear impression more visible again, for instance.
By positioning the light source at an oblique angle, we can try to reintroduce the contrast and shadowing that made the trace stand out in the overview image. Unfortunately, in this case, these efforts are not particularly successful.
The more obliquely we position the light from our external flash, the more the texture of the plastic surface becomes emphasized – often overpowering the actual trace.
On the other hand, the more directly we attempt to flash straight onto the trace, the more surface glare becomes dominant, reducing the visibility of the shoeprint even further.
In a situation like this, it’s time for one of my favorite lighting techniques: cross-polarized flash photography.
This involves placing a polarizing filter in front of the camera lens and a second on the external flash, rotated 90 degrees relative to each other.
This setup eliminates surface reflections effectively – including strong or metallic glare – and allows the trace to become clearly visible again.
After this brief excursion into forensic photography, let’s return to image processing and open our photo of the shoeprint fragment in Amped FIVE.
Forensic Shoeprint Analysis in Amped FIVE
Just like with fingerprints, the goal when processing footwear impressions is to have the trace appear dark against a light background.
To achieve this, we invert the image in Amped FIVE using the Negative filter from the Extract filter group.
Next, we’ll adjust the contrast in the image using the Smart Adjust filter from the Adjust filter group.
In this case, we achieve a good result by applying the filter in “Darken” mode.
As with all contrast and brightness adjustments, it’s a good idea to activate the saturated pixel warning in the Histogram tool.
Amped FIVE will then highlight the areas of the image that are overexposed or underexposed. The red color indicates overexposed regions and the blue underexposed ones.
As long as these saturated areas do not lie within our region of interest, they are not a concern for our processing workflow.
In the next step, we convert the image to grayscale.
To do this, we use the Grayscale Conversion filter from the Channels filter group.
For a direct comparison between the partial footwear impression and a shoe recovered from a suspect, the image must be properly scaled so that any printout matches the original trace in actual size.
The latest update of Amped FIVE (version 36648) includes improvements to the Resize 1:1 filter. It allows users to perform this conversion while preserving the original pixel count, ensuring that image quality remains fully intact.
To carry out the 1:1 conversion, we begin by opening the Resize 1:1 filter from the Edit filter group. We then draw a long, straight line along the visible scale in the image, placing both endpoints – Point 1 and Point 2 – as precisely as possible in the center of the scale markings.
Next, we enter the known length of the line as the World Distance in the Filter Settings tab – in our case, “5 cm”. Under Output Mode, we select “Embed DPI Metadata”. After clicking Apply, Amped FIVE calculates an output DPI of “1170.6138”.
This means that if the image were printed, the scale on the print would correspond exactly to the physical scale present in the original scene. At the same time, the image retains its full resolution and pixel integrity – an essential requirement for reliable forensic comparison.
As a final step, we can use the Annotate filter from the Presentation filter group to insert a directional arrow into the image, indicating the orientation of the trace. We can also add a label or description.
If we want to directly compare the suspect’s shoes with our partial footwear impression during the investigation, we can easily do this using the Video Mixer filter from the Link filter group.
In the Filter Settings panel, we select the two images we want to compare under Input. Then, in the Blend tab, we choose the option “Side-by-side Vertically” to display both images clearly, one above the other, for direct visual comparison.
Reporting with Amped FIVE
As with any forensic video or image processing, it is essential to document all modifications made during the digital enhancement or restoration of footwear impression evidence. These changes must be clearly and transparently communicated. The expert responsible for comparing the evidence with reference impressions should fully understand the nature and extent of the alterations. Furthermore, these modifications must be documented in a reproducible form that complies with audit trail requirements.
This can be achieved in a simple and intuitive way using the Amped FIVE Report. The report not only includes all relevant details related to the process but also provides references to scientific publications that validate the techniques used.
The report can be generated through the Projects menu. A pop-up window then appears, offering a wide range of customization options that allow users to adjust the format and layout to suit their documentation needs.
Conclusion
Footwear impressions are a valuable form of physical evidence. They can provide important information about a suspect’s movements, approach and exit paths, and in some cases, even allow for a direct comparison with a specific shoe. To make use of their full forensic potential, these traces must be documented and processed carefully and systematically.
As demonstrated in this article, Amped FIVE offers a comprehensive set of tools for the digital forensic processing of footwear impressions. The software supports a structured workflow ranging from basic contrast optimization and grayscale conversion to more advanced steps like 1:1 scaling and side-by-side comparisons. It is transparent, reproducible, and suitable for forensic evaluation.
In addition, overview photographs can be easily enhanced with relevant information using the Annotate filter, enabling the creation of clear, well-structured visuals. This forms a solid foundation for a complete and professionally presented image report.
When combined with good photographic practice and attention to situational context, even partial or hard-to-see shoeprints can be processed in a way that allows them to be used effectively in casework and court.
