In our exclusive clip from 'Ed Kemper', the serial killer explains why he killed his grandparents all those years ...

Those of you who have watched Mindhunter on Netflix already know how chilling Ed Kemper is. But have you ever wondered who brought this terrifying yet strangely charismatic serial killer to life?

The FBI were forced to change the way they interviewed serial killers after one made a horrifying threat to an agent ...