Green’s Dictionary of Slang

nicking n.

[nick v.1 (6)]

an arrest.

[UK]G.F. Newman You Flash Bastard 40: But complaints were even arising from the unimportant nickings nowadays, and they were hampering police efficiency.
[UK]G.F. Newman A Prisoner’s Tale 16: He would have taken his nicking had he really been involved in the blag and it had come on top.
[UK]J. Cameron Brown Bread in Wengen [ebook] ‘[L]ikes to make a nicking just before he finishes so he has to stay on for the paperwork, three hours’ overtime’.
[UK]N. ‘Razor’ Smith A Few Kind Words and a Loaded Gun 12: One of the things we had learned from previous nickings was never to keep evidence around.