Yet, Allen was charged with the crime — after police took an unusual step. As the Oregonian first reported Friday, investigators used Photoshop to digitally alter his mug shot, covering up his distinctive tattoos. Two of the tellers, who weren’t told that the image had been edited, subsequently picked him out of a photo array of five similar-looking men and identified him as the robber.

Now, a federal judge in Oregon is tasked with determining whether that crucial evidence should be thrown out of court, and whether Allen’s rights were violated. His attorney, Mark Ahlemeyer, argued that the question has weighty implications, given that today’s technology makes it easier than ever to manipulate a photograph.

If covering up a suspect’s prominent facial tattoos is considered fair game, the federal public defender wrote in a recent motion, “there would presumably be nothing wrong with adjusting various pixels to make someone’s face appear slimmer, so long as the government’s theory was that the suspect had gained weight since the crime.”

Allen faces three counts of robbery and one count of attempted robbery, all stemming from holdups that took place in northeast Portland in early April 2017. The culprit, nicknamed the “Foul Mouth Bandit” by police because of his frequent use of profanity, made trips to four banks and credit unions over the course of four days, each time claiming he had a gun and demanding cash. All but one of the tellers complied, and the robber ultimately walked off with more than $14,000.

That same month, Allen was arrested after police stopped him on the freeway for driving a car with no license plates, headlights or taillights. According to a criminal complaint filed in the U.S. District Court of Oregon in May 2017, officers found a glass pipe inside his pocket. Another pipe, which appeared to have drug residue on it, was underneath the driver’s seat.

Later, police got a call from a tipster who knew Allen through a mutual friend, and asked to remain anonymous for his safety. The tipster said his friend had shown him Allen’s mug shot, along with surveillance footage of the serial bank robber that appeared on KPTV. His head “immediately started spinning,” he said, explaining that the robber looked just like Allen, but without the tattoos.

Though one of the tellers had mentioned seeing faded tattoos on the robber’s neck, and another had noticed tattoos on his hand, none had described him with any ink on his face. Investigators subsequently used Photoshop to paint over Allen’s tattoos, and showed them to the tellers in a double-blind lineup, court filings say. According to the criminal complaint, only two of the four tellers identified Allen as the robber — one picked a different man from the lineup, while another was unable to decide.

Police also searched the car that Allen had been driving when he was arrested, which was full of clothing and looked like he had been living in it. They found several black hooded sweatshirts, two pairs of gray sweatpants, one pair of burgundy sweatpants, and a gray ski mask, which they said matched the clothing that the “Foul Mouth Bandit” had been wearing during two recent robberies.

Last month, when Allen’s attorney discovered his client’s mug shot had been digitally manipulated before it was added to a lineup, he filed a motion to have the evidence thrown out of court. In response, prosecutors argued the robber’s “immutable facial features” looked enough like Allen’s to justify adding him to the photo array, noting that he could have put on makeup before committing the robberies.

Allen “should not reap a windfall because the investigators were able to take steps to counteract his efforts to disguise his identity,” Assistant U.S. Attorney Paul T. Maloney wrote. By using Photoshop to paint over Allen’s tattoos, he argued, investigators simply “applied the digital equivalent of makeup."

Police have also justified the move by arguing that Allen’s tattoos could have been distracting to witnesses tasked with picking out the culprit from a photo lineup. During a Wednesday hearing, Portland Police Detective Brett Hawkinson testified the point of altering the mug shot was to “mask things that would stand out,” the Oregonian reported.

Ahlemeyer, the defense attorney, claimed the Photoshop job had a different motivation: It made his client look more like the perpetrator. Admitting the results into evidence could be a “slippery slope,” he argued.

“If a witness reports that a perpetrator did not have any front teeth, can the government simply black out a suspect’s teeth on the theory that it could be done with cosmetics?” he wrote. “Or if a suspect’s skin color is too dark or too light as compared to objective video evidence, can the government simply press a few strokes on a computer keyboard and adjust the color to match that objective evidence?”

Those questions largely haven’t been tested in court before, but Allen apparently isn’t the only one whose mug shot was digitally altered by the Portland Police Bureau. According to the Oregonian, Mark Weber, the forensic criminalist who “painted over the tattoos,” testified he had edited other suspects’ photos for lineups before and didn’t write up a report because the police department doesn’t require it.

U.S. District Judge Marco A. Hernandez said he plans to issue a written ruling on the issue soon, the paper reported.