An Enterprise transporter technician in 2266 who forgot that the Tantalus V penal colony was protected by a security screen and earned a dry reprimand from Captain Kirk.
Lieutenant Berkeley mans the transporter in the opening scene of the episode Dagger of the Mind, as the Enterprise delivers supplies to the Tantalus Penal Colony and takes on a cargo crate in return.
He cannot get the transporter to lock on and is baffled until Kirk reminds him that a prison is shielded and must lower its force field first. The captain suggests that he acquaint himself with penal colony procedures.
The crate he then beams aboard hides Dr Simon van Gelder, the colony's deranged assistant director, who climbs out once the room is quiet and overpowers him before making for the bridge to demand asylum. He was played by Larry Anthony.