This post from Psychology and Crime News links to this ABC Radio National story about the purported widespread use of brain scans in criminal cases. A quote from the MP3 file available at ABC (emphasis added):

‘But officer, my brain made me do it!’ Brain scans are becoming commonplace as evidence in US courts, in the bid to convict offenders or free them. But is the technology half-baked? Can we biologically categorize people as criminals - mad, bad and dangerous to know? Free will, privacy and personal responsibility are all up for grabs in the collision between science and the law.

There have been a number of stories lately suggesting that brain scans are frequently used in criminal cases. I'm a bit skeptical of these claims and would be interested to hear from readers if they've seen brain scans used in criminal (or civil) cases they've encountered.