- 1: Types of Evidence
- 2: Types of Crime Scenes
- 3: Evidence Collection
- Collection Priority
- Control Samples
- Reference Sample Collection
- Equipment
- Procedures
- Biological Evidence Packaging
- Blood and Body Fluid Collection
- Hair and Fiber
- Wet Stains on Absorbent Surfaces
- Special Situations
- Wet Stains on Nonabsorbent Surfaces
- Dry Stains on Absorbent Surfaces
- Dry Stains on Nonabsorbent Surfaces
- Collecting a Sample From a Smear
- Evidence Marking
- Packaging for Transport
- Chain of Custody
- Preserving Evidence
- Reporting
- Testifying
- Summary
- 04: CODIS
Control Samples
Home > 3. Evidence Collection > Control Samples
Control samples, sometimes referred to as substrate samples, are swabbings or cuttings from an unstained portion of the surface material near the recovered stain. The control sample should be packaged separately and clearly labeled. A laboratory may use the substrate samples as a control to confirm that the results of the test performed were brought about by the stain and not by the material on which it was deposited. Additionally, the laboratory can use these controls to troubleshoot unexpected results.
Click here for a video of a control sample collection procedure.
