List of serial killers by number of victims

A serial killer is defined as a person who kills three or more people, in three or more separate events over a period of time. There are gaps of time in between the killings, which may comprise of a few hours up to many years. This list shows serial killers in order of how many victims they had. In many cases, the exact number of victims assigned to a serial killer is not exactly known, and even if that person is convicted of a few, there can be the possibility that he/she killed many more.
The second column in the table states the number of victims that were definitely assigned to that particular serial killer. The third column states the number of other possible victims that the killer could also have murdered. Some of these crimes are yet to be solved, but have been included because they are notorious or clearly the work of a serial killer, despite nobody being caught.