How credible are lie detector tests?
By Gareth Evans BBC News
1 hour ago
Image caption There are calls for Brett Kavanaugh to take a lie detector test as part of an investigation into alleged sexual misconduct
In a secure basement room of the US Capitol building, senators are reading a secretive FBI report into allegations of sexual misconduct made against Supreme Court nominee Brett Kavanaugh.
The contents of the report are not meant to be revealed, and there has been some criticism that the scope of the investigation has not been wide enough.
Throughout the investigation senior Democrats have called for Mr Kavanaugh to take a lie detector test. One of his accusers, Christine Blasey Ford, has already done so.
But how accurate are these tests? And how do they work? Let's start with the basics...
https://www.bbc.com/news/world-us-canada-45736631
