Detectives investigating a robbery that occurred in Garston are appealing for witnesses and information.
The man grabbed hold of the case the custodian was carrying and then punched him in the face, causing him to drop the case.
The offender then ran away with the case in the direction of York Way. He is described as wearing dark clothing, included a hooded top, which had the hood up.
Detectives from the Watford Local Crime Unit are investigating.
Detective Sergeant Ian Siggery said: “Although understandably shaken, thankfully the custodian was not seriously injured and did not require hospital treatment.
“Two potential witnesses to this offence approached him after the incident – they are described as an Asian man and a white woman – I would like to speak with these people as they may be able to assist my team with the investigation.
“Additionally, it is believed two males were on a pedal cycle in the area at the time of the incident and may have been in possession of a case. They were riding in the direction of York Way, towards Cow Lane.
“If you saw these males, know who they are, witnessed the incident or have any other information in relation to the robbery please contact my team on 01923 472 970, quoting crime reference C4/18/632.”
Alternatively, you can contact the independent crime-fighting charity Crimestoppers anonymously on 0800 555 111 or through their Anonymous Online Form at www.crimestoppers-uk.org. No personal details are taken, information cannot be traced or recorded and you will never need to go to court.