ESLA (Electrostatic Dust-Print Lifter)
Definition
A device that applies a high-voltage static field to a metallised film, attracting dust particles from a footwear impression on a hard surface without contact with the impression itself.
- Full name
- Electrostatic dust-print lifter
- Mechanism
- High-voltage static field applied to a metallised film
- Target evidence
- Dust and residue footwear impressions on hard surfaces
- Contact with impression
- None, non-contact lifting method
Common questions
What kind of footwear evidence is ESLA used for?+
It recovers dry, dusty, or residue impressions on hard non-porous surfaces such as floor tiles, vinyl, or paper, where the mark is made of loose particulate rather than a moulded three-dimensional indentation.
Why is a non-contact lifting method preferred over photography alone?+
The electrostatic field pulls dust particles onto the film without pressing on or disturbing the original mark, preserving fine tread detail that photography under oblique light can miss or that physical lifting tape could smear.
Can ESLA recover impressions that are invisible to the naked eye?+
Yes. It can lift latent dust impressions left by footwear on surfaces where the deposit is too faint or thin to be seen under normal lighting, making it useful as a first non-destructive step before other enhancement techniques.
Related terms
- Class Characteristics (Footwear)
- The manufactured outsole design features shared by all examples of a specific shoe model: tread pattern, size, shape, and logo placement.
- Dental Stone
- A gypsum-based casting material harder and finer than plaster of Paris. Preferred for forensic 3-D casts because it captures detail at the...
- Perpendicular Camera Alignment
- The requirement that the camera lens be directly above the impression centre with the sensor plane parallel to the impression plane; prevents...
- R V. Mohan (1994) + White Burgess Langille Inman (2015)
- Canadian Supreme Court framework for forensic-expert admissibility: Mohan sets relevance + necessity + qualification + no exclusionary rule; White Burgess adds an...
- Randomly Acquired Characteristics (RACs)
- Post-manufacture features (cuts, gouges, embedded material, crack patterns) unique to a specific shoe sole or tyre; the highest-level individualising features in impression...
- SICAR (Shoeprint Image Capture and Retrieval)
- FBI and Foster and Freeman (UK) outsole design database used for class-characteristic database searches; referenced in US, UK, Australian, and Canadian forensic...
- Snow-Print Wax
- A spray wax applied in thin coats to snow impressions before casting to provide a thermal barrier, allowing Dental Stone casting without...
- Subclass Characteristics (Footwear)
- Features shared by a subset of shoes from the same mould or production batch; may mimic individual characteristics if not properly distinguished.
- SWGTREAD
- Scientific Working Group for Shoeprint and Tire Tread Evidence; US body that developed the dominant guidelines for footwear and tyre-mark examination, class-subclass-individual...
- Tracking Evidence (TE) Database
- FBI database of tyre tread design patterns, used for class-characteristic identification in tyre-mark cases; accessible to partner agencies internationally.
- Treadmate
- RCMP database of outsole designs for footwear comparison, used by Canadian forensic laboratories and accessible to partner agencies.