Introduction: A Revolutionary Advancement in Fingerprint Detection
Bethany Krebs, a fourth-year forensic science student at the University of Toronto Mississauga, is pushing the boundaries of traditional fingerprint detection methods with a groundbreaking new technique. Instead of the conventional dusting method, Krebs proposes a more efficient and economical solution: sandblasting. Her innovative approach promises to transform how forensic teams collect latent fingerprints at crime scenes, particularly when time and resource constraints are critical.
The Conventional Dusting Method: Limitations and Challenges
Traditional fingerprint detection relies on using a soft brush made of camel hair, fiberglass, or feathers to apply fine powder—typically composed of materials like aluminum, graphite, or iron—to surfaces at crime scenes. The powder adheres to natural skin secretions, such as sweat or oils, left in latent prints, revealing the unique ridge and furrow patterns of fingerprints.
While effective, this process can be slow and laborious, especially when covering large areas. The technique requires precision, as too much pressure or an improperly balanced brush can damage the delicate prints. For crime scene investigators, the time-consuming nature of this method can impede their ability to gather evidence swiftly, which is crucial in investigations where time is of the essence.
The Sandblasting Technique: A Game-Changer in Forensics
Krebs’ innovative solution to this challenge involves using a sandblasting gun powered by an air compressor to spray a fine, fluorescent yellow cornstarch powder over the surface in question. This method not only speeds up the process of fingerprint detection but also minimizes the risk of damaging the prints. By using cornstarch, a safer and more affordable substance than traditional fingerprint powders, Krebs’ technique provides a more practical and non-toxic alternative for aerosolized application.
The cornstarch powder settles onto latent fingerprints as a fine mist, without the need for physical contact. This contactless application reduces the risk of smudging or damaging the prints, offering a higher success rate for developing fingerprints in comparison to the traditional brush-and-powder method.
The Experiment: Testing the New Approach
Krebs conducted her experiment at the University of Toronto’s Crime Scene House, a specialized facility designed for forensic training. With guidance from forensic identification instructor Wade Knapp and lab technician Agate Gapinska-Serwin, she selected six common household surfaces to test her method: painted drywall, galvanized steel, treated hardwood, ceramic tile, laminate countertop, and glass.
She invited two friends to touch the surfaces, leaving behind 144 fingerprint samples. Using a gravity-feed sandblasting gun, Krebs sprayed fluorescent cornstarch powder over each surface and then photographed the fingerprints to assess her findings.
Results: Promising Success with Sandblasting Fingerprints
Krebs’ results were impressive. Of the 144 fingerprints, 100 were fully developed, and 10 were strongly developed—enough to provide clear identification. This success rate of 76% demonstrates the potential of sandblasting to replace or complement traditional dusting methods, particularly in large or complex crime scenes where speed and precision are essential.
The contactless nature of sandblasting significantly reduces the risk of damaging prints, making it a more reliable technique in circumstances where fragile or poorly visible fingerprints are present.
Advantages of the Sandblasting Technique
- Efficiency: Sandblasting provides faster results than traditional dusting, making it suitable for large crime scenes.
- Reduced Damage Risk: The contactless method prevents smudging or erasing delicate fingerprints.
- Cost-Effective: Using cornstarch powder, a more affordable and readily available alternative to traditional powders, makes the method economical.
- Safety: Cornstarch is less toxic than conventional fingerprint powders, offering a safer option for forensic investigators.
- Versatility: The technique can be applied across a variety of surfaces commonly found in crime scenes, as demonstrated in Krebs’ experiment.
Future Implications: Publishing and Practical Applications
Encouraged by her findings, Krebs is exploring opportunities to formally publish her research and hopes to see her technique adopted by forensic teams globally. If successful, sandblasting could revolutionize the way investigators collect evidence at crime scenes, offering a faster, safer, and more efficient alternative to conventional methods.
Conclusion: A Bright Future for Forensic Science
Bethany Krebs’ innovative sandblasting technique represents a significant leap forward in forensic science. By challenging the limitations of the conventional dusting method, her research paves the way for more effective and economical approaches to fingerprint detection. As forensic teams seek to improve efficiency and accuracy in crime scene investigations, Krebs’ method could play a crucial role in the evolution of forensic practices.
