Hammer spur impressions often are obliterated and subsequently overlooked when fingerprints are taken, although their presence enhances the probability that the wound was self-inflicted. The hammer spur impressions are caused when the firearm is cocked in the single-action phase, causing identifying features of the hammer -machine marks, outline of the hammer, size and shape, and contours formed through wear or damage. Such impressions may remain for several hours after death. Photographs should be taken in daylight, with and without a flash, prior to casting or lifting. The impression may be enhanced by a light dusting with black fingerprint powder. A lift may be made by lightly brushing the finger with a powder brush (without adding any more powder) and lightly placing a piece of cellophane tape over the finger. The tape then can be placed on a card. A cast can be made using Mikrosil or other casting material, mixed to an appropriate consistency, and spooned onto the finger. The cast should be removed after hardening. The weapon, together with this evidence, should be submitted to a toolmark/firearm examiner for a comparison of both class and accidental characteristics. 2 footnotes and photographs.