Calling card (crime)

A spider is the calling card for the criminal gang in Fritz Lang's 1919 film, The Spiders

A calling card is a particular object sometimes left behind by a criminal at a scene of a crime, often as a way of taunting police or obliquely claiming responsibility. The name is derived from the cards that people used to show they had been to visit someone's house when the resident was absent. A calling card can also be used as an individual's way of telling someone they are alive after they have run away or disappeared without revealing themself or having direct contact with that person. It is often left at a bed side table while the person is asleep.

Historical examples

Examples in fiction