This is the second video clip (4 mins 30 secs) in the pack The test is positive: What are the odds it's wrong?

See video
Expert: 

Philip Dawid is professor of statistics at the University of Cambridge.  He also acts as an expert witness in legal cases where statistics or probability are issues.

Research Interests: Foundations of probability and statistics; evidential reasoning; causal inference; graphical models; forecasting systems; DNA profiling.

Email address: APD[at]statslab.cam.ac.uk