A 16-year-old boy stands accused of carrying a knife around a Hatfield leisure complex.
Shoppers at The Galleria told police they had seen a person carrying a knife inside the complex at around 2.30pm on Thursday, August 25.
Hertfordshire Constabulary has since confirmed officers arrested a 16-year-old on Saturday, August 27, in connection with the report and charged him with possession of a knife.
Sergeant Alex Smedley, from the police's Welwyn Hatfield Safer Neighbourhood Team, said he hopes the public feel reassured that officers are taking knife crime seriously.
Sergeant Smedley said: "Our team remains committed to tackling knife crime and if you have any concerns that someone you know is carrying a knife, I urge you to report it to us.
"If you would prefer to stay anonymous you can also contact the charity CrimeStoppers which is independent from the police."
He added: "I would like to thank The Galleria for their cooperation and support on this investigation."
The 16-year-old boy is due to appear at St Albans Youth Court on Wednesday, September 7.
Officers said they used CCTV in their investigation to make the charge.
Hertfordshire Constabulary urged members of the public to report knife offences online at https://www.herts.police.uk/, by phone on 101, or - if a crime is in progress - by phone on 999.
Anonymous CrimeStoppers reports can also be made online (https://crimestoppers-uk.org/) or by phone on 0800 555 111.
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