He killed his youngest victim by forcing the man's wife to hold the needle

Harold Shipman arrived at the home of Peter Lewis at 7pm on New Year's Day, 1985. He carried his doctor's bag and was escorted by his wife Primrose, who sat on the sofa throughout a sequence of events which were to make Mr Lewis her husband's youngest victim.

As a middle-aged man, 41 years and two days old and being cared for by his intelligent, articulate school teacher wife, Mr Lewis was not the typical Shipman victim. Yet he was every bit as weak as the elderly ladies who had provided the GP with such easy targets since 1975. He had just been diagnosed with inoperable cancer which had spread from his stomach and had returned home from hospital on Christmas Day 1984 to die.

Shipman liked to kill the terminally ill because they brought less risk of detection and made him feel less "morally culpable", according to Dame Janet Smith. It explains his first choice of victim, 93-year-old Ann Cooper. He often chose the terminally ill if the threat of detection had forced him into a break from murder – as if "entering the pool at the shallow end to see if he could still swim", the inquiry report said.

But this murder was chilling even by Shipman's standards, since he even asked Mr Lewis' wife to hold the needle as he injected the lethal diamorphine. Mrs Lewis – now remarried as Muriel Hamilton – immediately fled in fright from the bedroom of the house in Denton, Greater Manchester. She had never helped with an injection before and did not expect to see the blood which confirmed the needle was in the right place.

When she returned to the bedroom, she saw Shipman with one hand around her husband's throat. She thought he was trying to strangle him, though when she asked the GP what he was doing, he said that he was preventing Mr Lewis from swallowing his tongue. She also recalled that Shipman said something like: "Give up lad, we've all had enough. We can't take any more."

The evidence of Shipman's behaviour and comments and Mr Lewis' imminent death after injection all pointed to unnatural killing, though Dame Janet was unconvinced that he tried to strangle Mr Lewis. As in other murders, he had placed his fingers in Mr Lewis' throat to prevent him choking on his tongue – an event which "might well cause the patient to struggle", according to Dame Janet.

There was no suggestion that Mr Lewis' death constituted euthanasia, Dame Janet concluded. "I think there is a real possibility that he wished to hasten Mr Lewis' end, as he would not wish to be called out again during the night."