scienceneutral
Cannabis and Witness Accounts: What the Study Says
Thursday, March 26, 2026
A recent study examined how marijuana use affects the recall of a crime video. Researchers employed the Sketch‑Cognitive Interview (Sketch‑CI), a specialized technique that helps witnesses reconstruct a scene mentally. They wanted to determine whether being high during the viewing or during questioning would impair memory accuracy.
Study Design
Participants: 131 adults divided into four groups
- High before & after the video
- High only before questioning
- Sober throughout
- Never used weed
- Each participant watched an online mock‑crime clip and then completed a Sketch‑CI interview.
- Afterward, they attempted three lineups that did not contain the perpetrator.
Key Findings
| Metric | Result |
|---|---|
| Detail recall (correct, incorrect, fabricated) | Nearly identical across all groups |
| Confidence in lineup selection | Similar for most, except those feeling very high |
| Intoxication level | Higher intoxication correlated with poorer fact recall and higher confidence in incorrect choices |
Implications
- The Sketch‑CI remains effective even when witnesses are under the influence of cannabis.
- Individual reactions to weed matter; those experiencing strong intoxication may still struggle with accurate memory.
Future Directions
- Test alternative interview techniques.
- Include a control group that receives no memory‑enhancing assistance to assess the true superiority of Sketch‑CI for cannabis‑using witnesses.
Actions
flag content
