Images of graffiti "tags" sprayed on walls across Dundee have been released in the hope that someone will recognise the culprits and inform the police.
Tags are symbols or words particular to each individual artist and will be known among friends and acquaintances.
Buildings which have been targeted recently include a school, university, shopping centre and electricity substation.
If this appeal proves a success, further pictures may be released.
Supt Colin Mackay, of Tayside Police, said: "We're hoping that when the public see these images someone will recognise the handiwork.
"Maybe they've seen the tag sprayed somewhere else in the city, or maybe they have spotted it on a book or school jotter.
"I know that some people regard graffiti as an expressive form of art, but when it appears on public or private buildings without authority it is nothing other than criminal and anti-social behaviour.
"We have been gathering a database of graffiti tags in Dundee for a number of years, whether through our police officers using mobile phone cameras or our scenes of crime officers taking photographs.
"By regularly researching these, we can link a large number of crimes together and make enquiries to hold the person responsible to account."