Britain's worst serial killer, Harold Shipman, murdered patients simply because they annoyed him, a forensic psychologist who studied the case details in a new Mail podcast.
On the latest episode of the Psychology of a Serial Killer podcast - which focuses on Shipman's many victims - Dr Andrew Johns, who testified at the national inquiry, exposed this chilling pattern.
Whether it was a frail patient whose son called too often, or an anaemic pensioner whose treatment inconvenienced him, Dr Johns reveals how trivial irritations became death sentences in Shipman's twisted mind.
Shipman, a GP, is suspected of killing 215-250 patients between 1975 and 1998 by injecting them with lethal doses of diamorphine (medical heroin).
Listen to The Psychology of a Serial Killer below or by clicking here.
