Modus operandi

A Latin phrase meaning the method of operation. Most commonly used in criminal cases, it is sometimes referred to by its initials, M.O. The prosecution does not have to prove any modus operandi, but identifying and proving it can help the prosecution to prove that it was the defendant that committed the crime charged.

Proving a modus operandi does not require the crimes to be identical, but the prosecution must make a strong and persuasive case of similarity between the crime charged and the other crimes. The prosecution may introduce evidence from prior or subsequent crimes to prove modus operandi only if the other crimes share particular and distinctive features with the crime charged. The features must be uncommon and rarely seen in other crimes, and they must be so distinct that they can be recognised as the handiwork of the same person.