Polygraph for pedophiles: how virtual reality is used to assess sex offenders

A controversial lab in Montreal is developing virtual reality images that can help build a profile of a pedophile, and determine their risk to society

In a maximum security mental health facility in Montreal is a "cave-like" virtual reality vault that's used to show images of child sexual abuse to sex offenders. Patients sit inside the vault with devices placed around their penises to measure signs of arousal as they are shown computer-generated animations of naked children.

"We do develop pornography, but these images and animations are not used for the pleasure of the patient but to assess them," said Patrice Renaud, who heads up the project at the Institut Philippe-Pinel. "It's a bit like using a polygraph but with other measurement techniques."