John Lamb of Wake Road, Peterborough, was out drinking late on Saturday, March 27, when he was searched by officers on Bridge Street.
It followed reports of an assault in the area and officers found Lamb was carrying a Stanley knife.
Lamb pleaded guilty to possession of a knife in public and was sentenced to eight months in prison at Peterborough Crown Court on June 15.
DC Melanie Mathieson said: “This case demonstrates how important search powers are. Carrying a knife is completely unacceptable and actually puts you at more risk of being seriously harmed. When a knife is involved arguments can escalate and easily result in someone being killed.”
For more information on knife crime, or if you know someone who carries a knife, visit the forces’s website here. If you don’t wish to speak to the police, contact Crimestoppers, anonymously, on 0800 555 111.