Courts continue to flirt with admitting fMRI evidence into court. While brain imaging techniques are uncovering great new information, it is not clear to me if they will ever be accurate enough to distinguish truth-telling from lying.
Wired Science has covered a legal case where fMRI brain scan lie detection data was offered as evidence. While the lawyer was initially hopeful, it was ruled inadmissible by the judge on the basis that judgements of witness credibility by the jury should be based on their impression of the witness.
via Mind Hacks: fMRI lie detection and the Wonder Woman problem.