(CNN) -- In crime labs across the country, law enforcement officials say more and more suspects are attempting to conceal their identity through fingerprint mutilation -- defacing the skin of their fingertips.
Earlier this month, federal prosecutors in Massachusetts charged three men in a conspiracy to "help illegal aliens evade detection through the mutilation or surgical removal of their fingerprints," according to a release from the U.S. attorney's office.
One of the accused, Jose Elias Zaiter-Pou, a doctor originally from the Dominican Republic, allegedly performed the procedure on patients for a fee $4,500.
According to Stephen G. Fischer Jr., a spokesman for the FBI's Criminal Justice Information Services, whose department receives approximately 200,000 fingerprints daily, methods of fingerprint mutilation can vary depending on the circumstance and the criminal.
"It can go from people chewing on fingers, using a knife, burning acid or cigarettes," Fischer said. "Or if you have a career criminal or someone who is a little more affluent, they might go to a surgeon."
While no hard data on fingerprint mutilations exist, Fischer says the FBI's forensics examiners have noticed the uptick over the last few years, though the reason is unclear.
But advancements in forensics technology have made fingerprint mutilation increasingly difficult to pull off, as even severely damaged fingers will provide investigators with clues.
"We can identify prints that we couldn't 10 or 15 years ago," Fischer said. "Basically, they're going through all this pain and expense for no reason."
Massachusetts State Police Detective Lt. Kenneth Martin said he believes there's a misconception among criminals that fingerprint mutilation will pay off.
"These are people that when [authorities] do find out who they are, they're usually wanted on some serious crime," he said.
Fingerprint mutilation is hardly a new concept. Notorious 1930s bank robber John Dillinger attempted to evade identification by using acid to burn his fingertips, according to the National Museum of Crime and Punishment in the District of Columbia.
According Joe Polski, chief operations officer of the International Association for Identification, an organization with 7,000 members, fingerprint mutilation is still a rare occurrence. And while it forces forensics experts to dig deeper to identify a suspect, Polski says the fact that the fingers have been adulterated is usually pretty obvious.
"Anybody who looks at those prints knows there's something wrong," he said. "Nature just doesn't make them like that."