PDQ
Definition
Paint Data Query database (RCMP-maintained). Cross-referenced from glass work when a vehicle is identified through paired glass and paint evidence.
- Maintained by
- RCMP (Royal Canadian Mounted Police)
- Database size
- 75,000+ OEM automotive paint formulations
- Primary use
- Vehicle identification via paint evidence in hit-and-run and forensic investigations
Common questions
What is PDQ and who maintains it?+
PDQ stands for Paint Data Query. It is an international database of automotive paint systems maintained by the RCMP (Royal Canadian Mounted Police). The database contains more than 75,000 original equipment manufacturer (OEM) paint formulations and is used globally by forensic labs to identify vehicles in hit-and-run cases and other investigations.
How is PDQ used in forensic casework?+
Forensic labs cross-query PDQ when paint evidence is recovered from a crime scene or victim. The database helps match paint samples to specific vehicle makes, models, and years. It is also cross-referenced alongside glass evidence when both materials are found together during vehicle identification work.
Why is PDQ important for hit-and-run investigations?+
Hit-and-run cases often depend on paint transfer evidence from the suspect vehicle. PDQ's comprehensive collection of automotive paint formulations allows forensic labs to narrow down the vehicle responsible by comparing recovered paint layers and composition to known OEM systems.
Related terms
- Binder
- The polymer matrix that holds pigments in place and bonds the paint to the substrate. Identifies paint type (alkyd, acrylic, polyurethane, epoxy)...
- 3R Rule
- The fracture-analysis mnemonic: Radial cracks form at Right angles to the Reverse (far, non-impact) side of the glass. Applied to the fracture...
- Alkyd Resin
- A polyester binder modified with fatty-acid chains from drying oils; cures by oxidative crosslinking and is characterised by FTIR ester carbonyl absorption...
- Basecoat
- The colour-bearing layer in automotive OEM paint; thin (10-30 µm), thermoplastic acrylic binder, contains colour and effect pigments.
- Clearcoat
- The transparent outermost layer of automotive OEM paint; thermoset acrylic-melamine, 40-60 µm, provides UV resistance and gloss.
- Concentric Fracture
- An arc-shaped fracture encircling the impact zone, produced by outer-table bending tension at a distance from the focal impact; always post-dates the...
- E-Coat
- Electrocoat primer, the first layer applied to a clean steel/aluminium substrate via cathodic electrodeposition. Usually black, epoxy-based, near-universal on modern automotive bodies.
- Effect Pigment
- Aluminium flake or TiO2-coated mica used in metallic and pearlescent automotive finishes; identified by SEM morphology and EDS elemental composition.
- Electrocoat (E-Coat)
- The first layer in automotive OEM paint, applied by cathodic electrodeposition of an epoxy-amine coating onto the bare steel shell; 15-25 micrometres...
- ENFSI EPG
- Expert Working Group on Paint (European Network of Forensic Science Institutes); produced the European paint-examination protocol and promoted EUCAP development.
- GRIM3
- Glass Refractive Index Measurement instrument, third generation. Hot-stage microscopy with sodium D-line illumination; reports RI to ±0.00002.
- Hackle Lines
- Fine secondary cracks on the fracture surface that fan from the origin, perpendicular to the moving crack front. Used to track crack...
Explained in these topics
- Glass Evidence: Fracture Patterns and Refractive IndexPaint Data Query database (RCMP-maintained). Cross-referenced from glass work when a vehicle is identified through paired glass and paint evidence.
- Paint Composition, Types and Binder ChemistryPaint Data Query; the RCMP automotive paint database with 75,000+ OEM formulations, used globally for hit-and-run vehicle identification.
- Paint Evidence: Layers, Coating Structure and Instrumental AnalysisPaint Data Query, the RCMP-maintained international database of automotive paint systems. Cross-queried by Indian SFSLs on flagship cases.