Nov 6, 2012
"Modus operandi" (also known as “MO”) is a new Latin words, literally translated as "method of operation", or a person or thing's normal mode of operation, from modus (“manner, method”) and operandi (“of working”). It is first known use in 1654. The term is used to describe someone's habits or manner of working.
In general, but more bias on criminology, “modus operandi” can be defined as “a method of procedure; especially : a distinct pattern or method of operation that indicates or suggests the work of a single criminal in more than one crime”.
The expression is often used in police work when discussing a crime and addressing the methods employed by the perpetrators. It is also used in criminal profiling, where it can help in finding clues to the offender's psychology. It largely consists of examining the actions used by the individual(s) to execute the crime, prevent its detection and/or facilitate escape. A suspect's modus operandi can assist in his identification, apprehension or repression, and can also be used to determine links between crimes.
In business operation, “modus operandi” is defined as “manner of operation; the means of accomplishing an act; especially, the characteristic method employed by a person in certain acts; the way one (who often is sly in business dealings) operates” . Therefore, the words “modus operandi” is often used in business settings as well, to describe a firm's preferred means of doing business and interacting with other firms.
 Douglas, J. E. and A. W. Burgess, A. G. 2006. Burgess, R. K. Ressler. Crime classification manual, John Wiley & Sons, p. 19-21
 Wiktionary, http://en.wiktionary.org/wiki/modus_operandi (6 November 2012).
 http://www.merriam-webster.com/dictionary/modus%20operandi (6 November 2012).
 Vronsky, R.2006. Serial Killers, Berkley Books, p. 412.
 Hazelwood, R. R, A. W. Burgess,2001. Practical Aspects of Rape Investigation, CRC Press, p. 517.
 Berg, B.L. 2008. Criminal Investigation, McGraw-Hill.