CCTV footage of a botched raid on a Watford jewellers aired on the TV programme Crimewatch last night.
The publicity push comes as part of a national effort to identify three men who dashed into Goldsmiths in the Intu shopping centre covering their faces with hoods and scarves and tried to smash their way into jewellery cabinets.
Staff were also threatened in the raid, which happened around midday on Friday, November 16.
However the trio were unable to get to the expensive watches in the cabinets they targeted and fled empty-handed, out of the shopping centre and across Exchange Road.
DC Kim Woodgate, from the Watford Local Crime Unit, said: "I would like to speak to anyone who recognises the men in these images. I would like to speak to them in connection with this incident.
"Anyone with information about the incident should contact police on the non-emergency number 101 quoting crime reference C1/12/5556. Alternatively, call Crimestoppers, the independent charity, anonymously on 0800 555 111."