RSF sentry (Inferno Earth)

In a parallel universe visited by the Third Doctor, an unnamed RSF sentry was stationed at the Inferno Project.

Biography
The sentry shot down RSF Private Wyatt, who was on top of a cooling tower, thinking that it was the Doctor. He was later stationed to guard the Doctor and the tranquillised Primord-mutated John Bromley in the complex's cell block.

However, Bromley's tranquillisers later wore off and the sentry was attacked and killed by the animalised technician. (TV: Inferno)

Behind the scenes

 * Roy Scammell also doubled for Derek Ware (RSF Private Wyatt) for Wyatt's fall from the tower due to concerns Ware might be injured, as he was also needed for studio recording. Thus, in the finished programme, Scammell essentially shoots himself.