Sudbury police have been instrumental in catching a man in the U-K connected with a child porn operation.   The department’s cyber-crime unit covertly monitored a chat room where participants talk about committing sexual offences against children.    The Sudbury crime unit identified a person of interest taking part in the discussions and tipped off police in London, England.    The London police worked with their colleagues in Derbyshire and arrested and charged a man with child porn offences.