A preconceived perception on the part of police investigators and detectives of a crime scenario or phenomenon based on past cases in which investigators became aware of a new type of scenario or phenomenon that was previously unknown to them but reaveal, being applied to a current case with similar elements and assumed to be identical to previous cases based on
past cases, statistics, personal assumptions, public opinion, hunches and other factors and then persued as such without objectivity or taking into account that although seeming similar the scenario may not be identical.
The police used a crime template to determine that when a child is killed in the home it's always the parents that are the killers due to statistics.