Horncastle cobbler, whose name appeared as a local preacher on a Horncastle Circuit plan for 1838-1839, when he was living at Goulceby. His interest in public executions led him to advocate the 'long-drop' system of hanging, arguing on humanitarian grounds that the condemned ought not to be choked to death. He showed that, by using a length of rope proportionate to the criminal's weight, the descent of the body would instantly dislocate the vertebrae and cause immediate death. As a public hangman in Lincoln from 1871, he successfully used this 'long-drop' method on Charles Peace and others. He died in Church Lane, Horncastle on 4 September 1883 and was buried in Trinity churchyard. The St. Stephen's Review (3 November 1883) printed a facsimile letter from Marwood, dated 4 June 1879, to 'an eminent person', which goes into detail about his method of hanging a prisoner in order to effect a quick death.