Parent-Child is one of the most common logical relationships between evidence entities. Typically this is a one-to-many relationship where the Parent can have many children and each Child must belong to a Parent. Parent-Child relationships should be used to capture the logical relationship between two entities where the Child entity cannot live without the Parent entity and the details on the Child are logically related to the details captured on the Parent. For example, student details may be held on a Student entity and student expenses on a Student Expenses entity. It this instance, Student Expenses could not exist without Student being present but Student could exist on its own.