Daniel Richard Cooper (1881–1923) was a convicted New Zealand baby farmer and illegal abortionist. In 1922, he was apprehended at a Wellington suburban property and in 1923 found guilty of murder and executed. His wife Martha Elizabeth Cooper was acquitted as being under his influence.
Daniel Cooper was born to Elizabeth Ure and George Cooper, in Burns, Otago on 18 October 1881. Later in life, he became a builder, although he experienced two periods of contact with the police over theft- once in Oamaru in 1902, and again in Palmerston North in 1907. By 1907, he had settled in Awamangu, Otago and married Marion Burns. The couple were itinerant and shifted to New Plymouth and then Gore, Southland, in 1916. By then, Daniel had joined the Seventh-day Adventist Church and sold a booklet entitled The Practical Guide to Good Health.
Tragedy struck when Marion died on 18 July 1917, in her eighth month of pregnancy. Although the initial diagnosis was pericarditis, the New Zealand Police reinvestigated the case in 1923, after Daniel Cooper was apprehended for suspected murder. Family friends expressed doubt about the circumstances of Marion's death; given that she was being treated for goitre with mercuric iodide, some argued that it was possible that he had intentionally overdosed his first wife with that medication
Given suspicions about his extracurricular activities occasioned by the death of his wife and other rumoured activities, Daniel Cooper was expelled from the Seventh-day Adventist Church of New Zealand on 2 January 1918, shortly after he had married his second wife, Martha (born 20 December 1893), a former book purchaser. Those rumoured activities may have included illegal abortion procedures. Daniel and Martha Cooper relocated one more time, to Newlands, a Wellington suburb, and set up an office in Lambton Quay, Wellington for their health activities in 1921. They ran a rest care and convalescent home for women, but the police raided the facility on 3 December 1922. The bodies of two newborn infants were found and Daniel and Martha were charged with murder, although Martha was later acquitted of any crime, given that there was no evidence that she had directly assisted her husband in his activities.