A body count is the total number of people killed in a particular event. In combat, a body count is often based on the number of confirmed kills, but occasionally only an estimate. Often used in reference to military combat, the term can also refer to any situation involving multiple killings, such as the actions of death squads or serial killers. The military gathers such figures for a variety of reasons, such as determining the need for continuing operations, estimating efficiency of new and old weapons systems, and planning follow-up operations.