Which step helps preserve physical evidence at a crash scene?

• A. Clear vehicles immediately
• B. Move evidence to a random location
• C. Photograph and measure
• D. Secure the scene, photograph and measure, and preserve vehicles and materials with proper packaging

Answer: (D)

Preserving physical evidence at a crash scene hinges on maintaining the scene’s integrity while thoroughly documenting what’s there. The best approach is to secure the scene to prevent contamination or disturbance, photograph and measure the scene to capture exact conditions and relationships between objects, and preserve vehicles and materials with proper packaging to maintain the chain of custody and prevent loss or alteration. This combination ensures you have an accurate, verifiable record for investigation and potential court needs.

Securing the scene stops people from altering or moving items that could reveal how the crash occurred. Photographing and measuring before any disturbance captures the original state—skid marks, vehicle positions, debris, fluid puddles, and other critical details in their true locations. Proper packaging and packaging protocols protect evidence from damage and contamination and establish a clear trail showing who handled it and when, which is essential for admissibility in any proceedings.

Choosing to clear vehicles immediately risks destroying important evidence such as impact points, deformities, and proximity relationships. Moving evidence to a random location disrupts the chain of custody and can create questions about authenticity. Simply photographing and measuring, while useful, leaves out the crucial steps of securing the scene and preserving items with proper packaging, which are necessary to maintain evidence integrity across the investigation.