Image: The Newgate calendar
Back in the 19th century, long before emails and text messages, people used telegrams for urgent communication. Telegrams were faster than snail mail but were relatively expensive: the longer the message, the greater the cost. Fighting crime demanded fast and secure communication.
To greatly shorten the length of telegrams between police stations, and to ensure secrecy, police in America used a code. Rather than encode each letter separately, Barnard’s code used a single English word to represent a fixed statement about a suspect. This was possible because a description of a suspect is formulaic and typically involves a small set of possible variables.
The code was organised according to the first few letters of each word used. For example, words beginning with cl- referred to clothing:
Suspect was wearing:
Cloak: a black frock coat
Clockwork: a black sack coat
Clothier: a pair of dark trousers
Here’s an example of four words from a police telegram written in Barnard’s code:
Trump, cold, saunter, locomotive
The receiver would use the code book to interpret this as:
The suspect is a sewing machine agent with small hands and a recent gunshot injury. He is likely to be found in a house of ill fame.
Check out the full text of Barnard’s Universal Criminal Cipher Code