Modus operandi

Modus operandi is a fancy way of saying "how someone does something." It's like when you play with your toys, you have a specific way of doing it. Maybe you always play with your dolls first and then move on to your cars. That's your modus operandi for playing with toys.

But modus operandi is usually used when talking about bad guys, like robbers or thieves. When they commit a crime, they often have a certain way of doing it. They might always break into a house through a window, or they might always wear a certain type of clothing. That's their modus operandi for committing the crime.

Police and detectives use modus operandi to figure out who might have committed a crime. They look for clues that match the way the criminal usually does things, so they can catch them and make sure they can't hurt anyone else.