Harold Shipman is the subject of BBC Two's new crime documentary, The Shipman Files: A Very British Crime Story on Monday night.
READ: 13 outstanding true-crime shows that are worth the watch
The doctor is considered to be Britain's most notorious serial killer, having been thought to have murdered around 250 of his patients by overdosing them, and was convicted of 15 murders in 2000. So how was the practitioner ever caught? Get the details here...
Harold Shipman is thought to have murdered up to 250 patients
A funeral director, Deborah Massa and Brooke Surgery doctor Linda Reynolds both reported their suspicions about Shipman's patients to the coroner of South Manchester Distract, pointing out a suspicious high mortality rate in elderly women in particular among those he treated. However, nothing was found in the investigation, which was then closed.
Suspicions were only heightened when one of his victims, Kathleen Grundy, appeared to have left £386,000 in her will to Shipman which reopened the investigation into him. It was then discovered that she had traces of heroin in her system, and he had posthumously added that she was an addict to his medical journal.
Taxi driver John Shaw was among those to alert police
The police then investigated 15 other cases, and discovered that the doctor would overdose his patients before falsifying their medical records.
READ: Where are notorious killers Rose West and Myra Hindley now?
A taxi driver, John Shaw, also reported Shipman after he noticed that several of his customers, who he had driven to the hospital in relatively good health, had died in his care. He eventually got in touch with police after 21 of his customers had died, and told the BBC: "I did consider getting in touch with the General Medical Council but...I had no confidence they would investigate Shipman... The fact that Shipman was such a well-respected figure in the community...made it all the more difficult to express my concerns publicly.
Kathleen Grundy was one of the doctor's victims
"They were so fantastic I couldn't grasp what my mind was telling me. I was equally frightened of being right as I was of being wrong."
Shipman was found guilty of 15 counts of murder in 2000, and given life imprisonment. The High Court judge said: "Finally you have been brought to justice for your wicked, wicked crimes. You abused the trust of these victims - you were, after all, their doctor. You used a calculating and cold-blooded perversion of your medical skills. You have shown no remorse.
READ: What is the true story behind David Tennant drama Des?
"In your case life must mean life. You must spend the remainder of your days in prison." Shipman died by suicide in 2004 at Wakefield prison, aged 57.
Like this story? Sign up to our newsletter to get other stories like this delivered straight to your inbox.