A murder suspect sits in a quiet room with electrodes placed on her head. The prosecution reads out its narrative of the crime and the suspect’s alleged role in it. As she listens, the machines record her brain activity and reveal that she experienced aspects of the crime that only the murderer could have. Her own memories, teased out by technology, have betrayed her. The verdict is guilty.

This scenario might seem far-fetched, but it actually happened in an Indian trial that took place in 2008. The judge took a brain scan as proof that the suspect had “experiential knowledge” about the crime that only the killer could have possessed. She was sentenced to life in prison. There has been