Axes, knives, truncheons and several home-made weapons are some of the feature pieces of a newly deposited collection within the Royal College of Physicians of Edinburgh archive. This paper uses examples from this unusual collection, consisting of 40 weapons and over 400 glass slides, to demonstrate the significance and contribution it has to understanding late 19th- and early 20th-century forensic science and medicine in Scotland. Previously belonging to the late Sir Sydney Smith, these objects and glass slides supplement the Sydney Smith paper collection that contains numerous casefiles spanning his career as a forensic practitioner both in Britain and internationally. The records from these collections offer the potential for understanding developments in early 20th-century forensic practices whilst highlighting some of Britain's macabre criminal history.