Conversation so far:
What was detection?
CANNOTANSWER.
Are there any other interesting aspects about this article?
case.
Between 17 April 1998, when the police abandoned the investigation, and Shipman's eventual arrest.
What was he being investigated for?
he killed three more people.
His last victim was Kathleen Grundy, who was found dead.
How did he kill them?
the last person to see her alive and later signed her death certificate, recording "old age" as the cause of death.
When was he caught?
September 1998.
How did the police catch him?
and was found to own a typewriter of the kind used to make the forged will.
Was he a serial killer?
The police then investigated other deaths Shipman had certified, and created a list of 15 specimen cases to investigate.
Who were some of his other victims?
cremation forms for elderly women that he had needed countersigned.

Question: How did he kill them?
Self-contained rewrite: How did Shipman kill the victims?