Warden (robot)
From Tardis Wiki, the free Doctor Who reference
The Wardens were the android guards of the prison planet Volag-Noc. Gurney, an ex-prisoner, hacked into the system and made himself the governor, replacing Governor Lok. The Wardens scanned visitors and prisoners with technology that read the person's brain (i.e their convictions and crimes). (DW: The Infinite Quest)