This can be used by forensic pathologists in discerning an approximate angle of entry and is important in investigations of gunshot wound victims, where evidence of the gunshot's origin is necessary to determine whether the death was homicidal, suicidal, or accidental. Generally, if the bullet impacts at an angle perpendicular to the skin surface, the abrasion collar will be symmetrical, concentric, round, and evenly-shaped. As the angle between the trajectory and the skin surface decreases, the abrasion collar becomes more distorted and often more distinct at the point of entry, having a semi-lunar or "half-moon" shape with the broadest width pointing in the direction of the gunshot's origin.[1] This is caused by the exterior of the bullet contacting and scraping over the skin's surface for a certain distance before penetrating the skin.[2]