The long arm of the law
What's the meaning of the phrase 'The long arm of the law'?
'The long arm of the law' is a rather clichéd way of referring to the police and to their assumed far-reaching crime-fighting and punitive powers.
The arm of the law, that is, the physical force that is used to put the law into practice, is the police.
The long arm of the law is intended to imply that, however far a criminal may run, the police's power will reach and that they will inevitably reach out and 'feel his collar'.
In recent times in the UK, where crimes like burglary are commonly not investigated let alone solved, the expression is often used ironically.
What's the origin of the phrase 'The long arm of the law'?
The expression is English in origin and dates from the 18th century. The first example of it that I can find in print is in the London newspaper The Public Advertiser, December 1767:
How difficult it is even for the Long Arms of the Law to prevent mutual Oppression, Avarice, Ambition and Excess.
In the USA the alternative form 'the strong arm of the law' was more widely used, although the 'long' variant is found in print there from the 1840s onward. The first use of it there that I have found is from the Wisconsin newspaper the Milwaukie [sic] Commercial Herald, July 1844.
A Mr Neville, of western New York, has married a Miss Amanda Drop, while having another wife. The long arm of the law dropped down on him, and walked him off to prison for bigamy.
Charles Dickens, while not coining the term, did much to popularise its use, in both the 'long' and 'strong' variants, in The Old Curiosity Shop, 1841:
The gamblers... pursued their course with varying success, until the failure of a spirited enterprise in the way of their profession, dispersed them in various directions, and caused their career to receive a sudden check from the long and strong arm of the law.
See also: the List of Proverbs.