Police investigating an upsurge in graffiti over the past two weeks discovered more of it recently beneath a train trestle on Riverside Street in Lewiston, shown here. The spray-painted graffiti there consists of the words "Evidence" and "Evolve," which also appear in at least four dozen other locations around the Twin Cities. Investigators say a Lewiston man and Auburn teenager are responsible for the graffiti and that they caused an estimated $20,000 damage to the buildings they targeted.

AUBURN - Police are looking for volunteers to help them clear away evidence. The spray-painted word, "evidence," that is.

In a recent spate of vandalism, that word and others have appeared on more than four dozen buildings around the Twin Cities.

"Graffiti is an unauthorized inscription, word, figure or design that is marked, etched, scratched, drawn or painted on any surface without the property owner's permission," Auburn's interim police Chief Phil Crowell said in a news release. "Unwanted, it diminishes the quality of our neighborhoods and the community."

In Auburn, police are asking residents to help by reporting locations where graffiti is found as well as information on those responsible.

In addition, Sept. 9 has been declared Graffiti Cleanup Day. From 9 a.m. until 1 p.m., police and others will be canvassing the city with cleanup crews and scrubbing graffiti from buildings, bridges, walls and other locations.

Anyone interested in participating can call Auburn police at 784-7332 or e-mail Crowell at pcrowell@ci.auburn.me.us .

"Graffiti or vandalism left alone only welcomes more," Crowell wrote. "Young people become bolder to damage property already damaged. We need to take pride in our community and eliminate graffiti."