Which workflow principle helps prevent cross-contamination by limiting movement through the scene?

Which workflow principle helps prevent cross-contamination by limiting movement through the scene?

• A. One-way workflow
• B. Two-way workflow
• C. Circular workflow
• D. Random workflow

Answer: (A)

Limiting movement through the scene to a single direction prevents contaminants from being carried back into clean areas. A one-way workflow creates a clean-to-dirty progression: investigators enter a controlled clean zone, don appropriate PPE, move through the scene in a planned sequence, collect evidence, and exit to a designated processing area without retracing steps. By avoiding backtracking, materials like dust, fibers, or chemicals are less likely to be transferred from evidence to locations or items that were previously untouched, preserving the integrity of each piece of evidence and maintaining the chain of custody. The other approaches would allow back-and-forth movement, increasing the chance of cross-contamination and mixing of materials.