Drug-fighting forces may have struck gold with a process that uses the precious metal to lift fingerprints from credit cards, plastic bags and bullet cartridges.
The first arrest using the gold-silver binding technique came just four months after it was developed by George Saunders at New Mexico’s Los Alamos National Laboratory.
Secret Service agents arrested a man in a 1989 embezzlement case after developing palm prints on a blank government check from a Pennsylvania military facility.
Today, “basically the whole world” is using the method, which is based on a technique used by biologists to stain proteins, said Coy Burns, chief of the identification and research branch of the Secret Service’s forensic division in Washington, D.C.
“It’s one of the most productive processes that’s been developed in recent times,” he said.
The technique enables investigators to lift prints off items that in the past were difficult to deal with, such as the plastic that bricks of marijuana are wrapped in and the adhesive tape used to keep it sealed.
“It’s going to make it easier not only to solve cases but to prosecute cases,” Burns said.
People from several countries met recently in Detroit to discuss the process.
Saunders said he came up with the technique after talking to acquaintances in the Secret Service who said they were looking for new ideas in fingerprinting.
“I was surprised at how easy it was to do,” Saunders said.
With the technique, fingerprints become visible when gold particles adhere to proteins in secretions left on an object that has been touched. The object is washed for about 30 minutes in colloidal gold, a buffer solution of citric acid that contains tiny particles of gold.
The object then is washed in distilled water to remove unbound gold particles, then bathed in a silver solution for five to 15 fifteen minutes. The silver enhances the image by filling in around the gold and highlighting the fingerprint.
“It’s like developing a photograph,” Saunders said.
Saunders’ process is more sensitive on plastics and other surfaces than a process that uses only silver to cling to the fingerprint, Burns said.
Although the process works best on plastics, it can be used on counterfeit money and other paper, he said.
“That’s one of the advantages, you can use it after you’ve used other techniques that didn’t work,” Saunders said.
It cannot be used on real cash, which contains a lot of protein-bearing flax and cotton, he said.
Under a technology transfer agreement, ODV Inc. of South Paris, Me., was granted an exclusive license earlier this year to market the fingerprinting process. ODV also manufactures kits for on-the-spot narcotics identification and crime lab investigations.
Before the company began selling the process, it was made available to law enforcement agencies in many countries by the Secret Service on a trial basis, the lab said.
ODV has sold about 100 fingerprinting kits, at $35 each, to law enforcement agencies, which mostly are using them for drug cases.