Doncaster residents are being asked to help with a campaign to catch those responsible for graffiti in the town.
The South Yorkshire Police "Who Did This?" initiative features posters with recent examples of graffiti.
The force wants members of the public to contact them if they think they know the offenders.
The campaign is being backed by Doncaster Council. The authority said it cost an annual £300,000 to clean up the damage caused by graffiti.
Police said anyone caught as a result of the campaign could face a £75 fine.