What is forensic evidence?
Evidence gathered for use in court.
Name three common myths about forensic evidence.
Polygraphs are accurate; People don’t confess falsely; Eyewitness memory is reliable.
What do polygraphs measure?
Pulse, blood pressure, respiration, skin conductivity.
What do polygraph measures actually indicate?
Physiological arousal, not necessarily deception.
Give an example of a guilty person who passed a polygraph.
Gary Ridgway (Green River Killer).
Define hit rate in lie detection.
Correctly identifying a lie.
Define false alarm rate in lie detection.
Identifying truth as lie.
What indicates chance performance in lie detection?
Hit rate equals false alarm rate.
What does ROC curve show?
Relationship between hit rate and false alarm rate; distance from chance line indicates accuracy.
Why are field polygraph tests less accurate?
Less controlled conditions than lab settings.
What is the main conclusion about polygraphs?
They are imperfect and unreliable alone but not entirely useless.
How many US exonerations existed as of 2024?
3499
What percentage of false confessions involve under-18s?
0.36
What percentage involve people with mental illness or disabilities?
0.69
Why do people make voluntary false confessions?
Attention, self‑punishment, protecting perpetrator, confusion.
Example of voluntary false confessor?
Henry Lee Lucas.
Why do compliant confessions occur?
Ending interrogation, avoiding threat, hoping for leniency.
Example of compliant false confession?
The Central Park Five.
Why do internalised confessions occur?
Memory distrust, persuasive investigators, psychological vulnerability.
Example of internalised confessor?
Jorge Hernandez.
Which interrogation tactic produced the most false confessions in Russano et al. (2005)?
Minimisation + deal.
Myth about memory?
Memory is like a video camera.
Why is eyewitness memory unreliable?
Reconstructive, distorted, not perfectly recorded.
What does the Jennifer Thompson & Ronald Cotton case illustrate?
High confidence can accompany inaccurate memory.
