Richard Freeman was born in Soho, London on 11 April 1862, the son of Ann Maria (nee Dunn) and Richard Freeman, a tailor. He was originally named Richard, and later added the Austin to his name.

He became a medical trainee at Middlesex Hospital Medical College, and was accepted as a member of the Royal College of Surgeons.

He married Annie Elizabeth Edwards in 1887; they had two sons. After a few weeks of married life, the couple found themselves in Accra on the Gold Coast, where he was assistant surgeon. His time in Africa produced plenty of hard work, very little money and ill health, so much so that after seven years he was invalided out of the service in 1891. He wrote his first book, 'Travels and Life in Ashanti and Jaman', which was published in 1898. It was critically acclaimed but made very little money.

On his return to England he set up an eye/ear/nose/throat practice, but in due course his health forced him to give up medicine, although he did have occasional temporary posts, and in World War I he was in the ambulance corps.

He became a writer of detective stories, mostly featuring the medico-legal forensic investigator Dr Thorndyke. The first of the books in the series was 'The Red Thumb Mark' (1907). His first published crime novel was 'The Adventures of Romney Pringle' (1902) and was a collaborative effort published under the pseudonym Clifford Ashdown. Within a few years he was devoting his time to full-time writing.

With the publication of 'The Singing Bone' (1912) he invented the inverted detective story (a crime fiction in which the commission of the crime is described at the beginning, usually including the identity of the perpetrator, with the story then describing the detective's attempt to solve the mystery). Thereafter he used some of his early experiences as a colonial surgeon in his novels.

A large proportion of the Dr Thorndyke stories involve genuine, but often quite arcane, points of scientific knowledge, from areas such as tropical medicine, metallurgy and toxicology.

He died in Gravesend on 28 September 1943.