This is an instance and clarification of extractor/ejector marks on casings. In Warwick 1816, a farm laborer was attempted and convicted of the murder of a youthful maidservant. She had been drowned in a shallow pool and bore the marks of violent assault. An posting showing in Scientific American in https://forensic-investigators01122.tblogz.com/the-best-side-of-forensic-investigation-41002620