STACEY: THIS IS FASCINATING. A SCIENTIFIC BREAKTHROUGH AT IOWA STATE UNIVERSITY HAS FOUND A NEW WAY TO USE FINGER PRINTS TO FIGHT CRIME. STEVE: AS KCCI SENIOR REPORTER TODD MAGEL SHOWS US, THEY HAVE FIGURED OUT HOW TO MEASURE THE AGE OF FINGERPRINTS AND WHEN A PERSON WAS AT THE SCENE OF A CRIME. >> WE ARE IN THE BASEMENT OF AN IOWA STATE UNIVERSITY CHEMISTRY BUILDING, WHERE STUDENTS AND THEIR PROFESSOR ARE USING THIS HIGH-TECH GEAR TO CHANGE THE WAY FINGERPRINTS ARE USED IN CRIME SCENE INVESTIGATIONS. >> I’M GOING TO DUST IT WITH THE BLACK CARBON POWDER YOU MAY HAVE SEEN ON TV SHOWS. REPORTER: ISU CHEMISTRY GRADUATE PAIGE HINNERS IS HELPING TO INVENT A BREAKTHROUGH. FOR YEARS SHE’S STUDIED HOW TO MEASURE HOW LONG A FINGER PRINT HAS BEEN DEPOSITED IN A CERTAIN SPOT. AND NOW WITH THE HELP OF ISU CHEMISTRY PROFESSOR YOUNG-JIN LEE THEY KNOW THE ANSWER. >> IT IS A BREAKTHROUGH. >> WE WERE DEFINITELY SHOCKED. >> WE CAN TELL HOW OLD IS THE FINGERPRINT WITHIN A FEW DAYS. REPORTER: LEE AND HINNERS DISCOVERED A WAY TO MEASURE CHEMICAL COMPOUNDS IN FINGER PRINTS. THEY FEED THE PRINT INTO A MASS SPECTROMETER. AND THEY BREAK IT APART WITH LASER BEAM. >> TYPICALLY ABOUT A QUARTER OF THE FINGER PRINT IS THE SIZE WE ANALYZE. REPORTER: THE SPECTROMETER CAN DETECT MICROSCOPIC LEVELS OF TRIGLYCERIDES, OR FAT LEFT IN A FINGER PRINT. FRESH PRINTS HAVE MORE FAT. THE FAT BEGINS TO FADE IN OLDER PRINTS. A FORMULA ALLOWS THEM TO DETERMINE HOW OLD A FINGER PRINT IS BY MEASURING THE MASS OR INTENSITY OF THAT FAT. >> YOU CAN SAY NOT ONLY WAS IT THIS PERSON, THIS PERSON WAS AT THE CRIME SCENE DURING THIS TIME, OR THIS PERSON WAS PRESENT DURING THIS TIME. >> IT CAN CHANGE THE LIVES OF SO MANY PEOPLE WHO ARE KEPT IN PRISON TO ARE INNOCENT. REPORTER: IT’S TAKE ISU 3 YEARS TO COME UP WITH FINGERPRINT DEVELOPMENT, IT MAKE TAKE ANOTHER TWO YEARS BEFORE IT CAN BE USED IN A CRIMINAL TRIAL.