I watched a very interesting show on TV a few weeks ago. It was called The Poisoner's Handbook and is based on the novel of the same name by Deborah Blum.
The show traced several real-life cases in 19th century New York where suspicious deaths had taken place. Coroners in that time were not required to have any expertise or credentials. As well coroners were paid by the case, which meant the faster they determined the cause of death, the more money they made. Many coroners accepted payment to alter a cause of death. The result was that often an incorrect cause of death was given.
Thanks to Charles Norris, New York's first scientifically trained coroner and his assistant Alexander Gettler, a highly trained toxicologist, determining causes of death became more accurate. Forensic science became a trusted tool when suspicious deaths ocurred.
The program was fascinating on many levels and if you get a chance you might want to watch it. It also points out that as genealogists we need to be aware of the times and the culture in which the death certificates of our ancestors were issued.