To minimize the number of murders, it is helpful to try to antipate the variables that determine it. The graphic above illustrates an attempt at a simple model using some candidate variables.

In this model, an event occurs during which a number of people are murdered (murders). The number of murders at the event is the result of a number perpetrators attempting to kill a number of people in a set of circumstances that provides opportunity for an attempt to be succesful.

Each perp is willing and capable of killing a number of people per unit time, which is the product of motive, means, and ability to use the means (measured as a kill rate - murders per unit time) at an event with maximum opportunity. The murders per event of a given time is the product of the cumulative kill rate for all of the perpetrators, the opportunity, and the time.

Mathematically, where motive, ability, and opportunity are each a number between 0 and 1:

Murders/Event = [ (motive * ability * means)_{Perp 1}+... + (motive * ability * means)_{Perp N} ] * opportunity * time

To reduce this number, the values of any or all of the variables can be reduced.