When the police arrested a suspect in a series of bank holdups in Portland, Ore., they took his mug shot and prepared to show it to witnesses in a photo array alongside images of five similar-looking men.

But there was a problem: The suspect had at least a half-dozen facial tattoos, but according to surveillance video and bank tellers, the robber had none.

This was nothing a little Photoshop could not fix.

The police used editing software to remove the tattoos from the picture of the suspect, Tyrone Allen, and presented his revised face to four tellers, at least two of whom identified him as the bank robber. Prosecutors in Portland said Mr. Allen may have applied makeup before the robberies and that investigators simply mimicked the possible disguise.

Mr. Allen's lawyer is asking a judge to throw the identifications out, The Oregonian reported this month, publicizing a practice that has drawn outrage from activists who say the police unfairly changed Mr. Allen's appearance to match witness accounts.