Akademik

mo·dus ope·ran·di
/ˌmoʊdəsˌɑːpəˈrændi/ noun [singular]
formal : a usual way of doing something; especially : the usual way that a particular criminal performs a crime

the murderer's modus operandi

Modus operandi is a Latin phrase that means “method of operation” in English. — called also MO

Useful english dictionary. 2012.