SCIENCE IN THE NEWS #2107 - FINGERPRINTS
By JERI WATSONTHIS IS SARAH LONG.AND THIS IS BOB DOUGHTY WITH SCIENCE IN THE NEWS, A V-O-A SPECIAL ENGLISH PROGRAM ABOUT RECENT DEVELOPMENTS IN SCIENCE. TODAY WE TELL ABOUT SOME OF THE LATEST DEVELOPMENTS IN FINGERPRINTING -- THE SCIENTIFIC STUDY OF THOSE SMALL LINES ON THE ENDS OF OUR FINGERS.LAST YEAR IN THE UNITED STATES, POLICE USED FINGERPRINTS TO HELP SOLVE THOUSANDS OF CRIMES. THEY ALSO USED FINGERPRINTS TO SAVE MANY OTHER PEOPLE FROM BEING FALSELY ACCUSED OF CRIMES.
LAWYERS ARE EXTREMELY PLEASED WHEN THEY CAN SHOW FINGERPRINT EVIDENCE IN COURT. FEW KINDS OF EVIDENCE ARE AS BELIEVABLE AS THE FINGERPRINT.
IT IS POSSIBLE FOR OBSERVERS OF CRIMES TO IDENTIFY THE WRONG PERSON. AND, JURIES SOMETIMES REJECT EVIDENCE PROVIDED BY BLOOD AND OTHER BODY SUBSTANCES.
YET NO TWO PEOPLE IN THE WORLD HAVE BEEN PROVEN TO HAVE THE SAME FINGERPRINTS. BECAUSE OF THIS, IN ALMOST ONE-HUNDRED YEARS,
THERE HAVE BEEN NO REPORTS OF MISTAKES IN IDENTIFYING FINGERPRINTS.THE IDEA OF IDENTIFYING PEOPLE FROM THE LINES ON THE FRONT SURFACE ON THE ENDS OF THEIR FINGERS IS NOT NEW. HISTORIANS BELIEVE THE CHINESE KNEW ABOUT FINGERPRINTS THOUSANDS OF YEARS AGO. THEY SAY ANCIENT CHINESE SIGNED DOCUMENTS BY PLACING THEIR THUMB ON THE DOCUMENT AFTER PUTTING INK OR OTHER DARK SUBSTANCES ON THE THUMB. THE THUMB IS THE FINGER ON THE SIDE OF THE HAND, AND DOES NOT LOOK SO SIMILAR AS THE OTHER FOUR FINGERS.
A NINETEENTH-CENTURY BRITON, WILLIAM HERSCHEL, PROBABLY WAS THE FIRST TO DEVELOP AN EASY WAY TO IDENTIFY FINGERPRINTS. BY EIGHTEEN-FIFTY-EIGHT, MISTER HERSCHEL WAS ABLE TO USE A SIMPLE FORM OF FINGERPRINT IDENTIFICATION. HE USED IT WHILE WORKING AS A BRITISH GOVERNMENT OFFICIAL IN BENGAL, INDIA.BRITISH SCIENTIST FRANCIS GALTON PROBABLY IS RESPONSIBLE FOR THE PRESENT SYSTEM OF FINGERPRINT IDENTIFICATION.
DURING THE EIGHTEEN-EIGHTIES, HE DEVELOPED THE SCIENCE OF STUDYING FINGERPRINTS. IT IS CALLED DERMATOGLYPHICS. IN HIS STUDIES, MISTER GALTON MADE AN IMPORTANT OBSERVATION. IN THE TWENTY YEARS THAT HE WORKED WITH FINGERPRINTS, HE LEARNED THAT THEY DO NOT CHANGE DURING A PERSON'S LIFETIME.
SOON AN ARGENTINIAN NAMED JAN VUCETICH (VOO-'SAY-TEACH) DEVELOPED A METHOD OF ORGANIZING FINGERPRINT INFORMATION SO THAT IT COULD BE USED IN CRIMINAL INVESTIGATIONS. FINGERPRINT IDENTIFICATION WAS PUT INTO USE IN THE ARGENTINE CAPITAL, BUENOS AIRES, IN EIGHTEEN-NINETY.THE BRITISH CRIMINAL-INVESTIGATION ORGANIZATION KNOWN AS SCOTLAND YARD OPENED A FINGERPRINT OFFICE IN NINETEEN-ONE. IN NINETEEN-FOUR, THE POLICE DEPARTMENT IN THE MIDDLE WESTERN AMERICAN CITY OF SAINT LOUIS, MISSOURI, ESTABLISHED THE FIRST FINGERPRINTING OPERATION IN THE UNITED STATES.
TODAY, THE UNITED STATES FEDERAL BUREAU OF INVESTIGATION HAS THE WORLD'S LARGEST COLLECTION OF FINGERPRINTS. THE F-B-I HAS IN ITS RECORDS THE PRINTS OF ABOUT TWO-HUNDRED-THIRTY-MILLION PEOPLE. OF THOSE, MORE THAN HALF ARE FROM PEOPLE INVOLVED IN CRIMINAL CASES. THE OTHER FINGERPRINTS ARE MOSTLY THOSE OF GOVERNMENT AND MILITARY EMPLOYEES.FINGERPRINTS CAN BE PRODUCED ON OBJECTS BECAUSE ALL HUMANS HAVE OIL ON THEIR SKIN. IT IS FOUND ALL OVER THE HUMAN BODY, INCLUDING THE ENDS OF THE FINGERS.
A PERSON TOUCHING AN OBJECT WITH HIS OR HER FINGERS LEAVES SKIN OIL ON THAT OBJECT. THE OIL CAN REPRODUCE THOSE SMALL FINGERTIP LINES, MAKING A FINGERPRINT. THIS IS TRUE IF THE PERSON TOUCHES WOOD, METAL, GLASS, OR EVEN OTHER HUMAN SKIN. THIS TYPE OF FINGERPRINT IS CALLED A LATENT FINGERPRINT. THAT MEANS IT IS TAKEN FROM A SURFACE OTHER THAN THE END OF THE FINGER ITSELF.WHEN POLICE FIND FINGERPRINTS IN THE AREA WHERE A CRIME HAS TAKEN PLACE, THEY COMPARE THEM TO THE FINGERPRINTS OF SUSPECTS. ALL POLICE DEPARTMENTS AND FEDERAL AGENCIES CAN CHECK FINGERPRINTS WITH FOLE, AMERICA'S FEDERAL OFFICE OF LAW ENFORCEMENT. THE OFFICE KEEPS THE FINGERPRINTS OF EVERY PERSON FOUND GUILTY OF A SERIOUS CRIME IN THE UNITED STATES. THESE PRINTS ARE ON A COMPUTER. LAW OFFICERS THEN CAN EXAMINE UNIDENTIFIED FINGERPRINTS FOR SIMILARITIES WITH MILLIONS OF OTHERS.GETTING THE FINGERPRINT MAY NOT BE EASY, HOWEVER. POLICE EXAMINING A CRIME AREA MUST BE CAREFUL NOT TO DAMAGE OR DESTROY EVIDENCE. THIS INCLUDES EVIDENCE THEY CANNOT SEE, LIKE FINGERPRINTS. GOOD POLICE TEAMS LIMIT THE NUMBER OF PEOPLE WORKING IN AN AREA WHERE THEY ARE INVESTIGATING A CRIME. THOSE WORKING USUALLY WEAR SPECIAL GLOVES SIMILAR TO THOSE USED BY DOCTORS DOING OPERATIONS. THAT PREVENTS THE POLICE FROM LEAVING ANY OF THEIR OWN FINGERPRINTS OR DAMAGING THOSE LEFT BY CRIMINALS.SOME SURFACES HOLD SKIN OIL BETTER THAN OTHERS. SO POLICE HAVE HAD TO CREATE METHODS TO MAKE A FINGERPRINT CLEAR AND EASILY SEEN.
THE EASIEST SURFACES TO WORK WITH ARE MATERIALS SUCH AS PLASTICS, WOODS AND METALS. TO DEVELOP A PRINT ON THESE MATERIALS, POLICE DROP A FINE POWDER OVER THE PRINT AREA.
GRAY POWDER SOMETIMES IS USED ON SURFACES SUCH AS GLASS AND SOME WOODS. DOCUMENTS AND PAPERS ARE MORE DIFFICULT SURFACES. TO FIND A FINGERPRINT ON THESE SURFACES, SPECIAL CHEMICALS MUST BE USED. FOR EXAMPLE, THE CHEMICAL NINHYDRIN (NIN-'HIGH-DRIN) PERMITS A FINGERPRINT TO BE SEEN BY THE HUMAN EYE WHEN EXAMINED THROUGH A SPECIAL DEVICE CALLED AN INFRARED LENS.THE MOST DIFFICULT SURFACE TO GET FINGERPRINTS FROM IS HUMAN SKIN. TO DEVELOP PRINTS LEFT ON THE SKIN, SCIENTISTS CREATED SPECIAL METHODS BASED ON THOSE USED FOR SURFACES LIKE PAPER. IN ONE SUCH METHOD, A PIECE OF PHOTOGRAPHIC PAPER IS PLACED OVER A SUSPECTED FINGERPRINT. NEXT, THE PAPER IS REMOVED. THEN IT IS COVERED WITH FINGERPRINT POWDER. IF A FINGERPRINT IS THERE, IT WILL APPEAR ON THE PAPER.FINGERPRINTS ARE CONSIDERED THE SAME WHEN A NUMBER OF AREAS LOOK THE SAME. THESE PLACES ARE CALLED MINUTIAE POINTS. IF ANY ONE POINT IN A FINGERPRINT IS DIFFERENT THAN ANY OTHER POINT, THE PRINTS ARE NOT THE SAME. IF ALL ARE THE SAME, THE FINGERPRINTS ARE SAID TO BE A MATCH.
BRITISH COURTS REQUIRE SIXTEEN AREAS OF MATCHING IF FINGERPRINTS ARE TO BE USED AS EVIDENCE IN A CRIMINAL CASE. IN THE UNITED STATES, THERE IS NO REQUIRED NUMBER OF MATCHING AREAS. HOWEVER, MOST FINGERPRINT EXPERTS WILL NOT IDENTIFY AS A MATCH FINGERPRINTS WITH FEWER THAN TEN POINTS OF SIMILARITY.IDENTIFICATIONS OF TWO OR MORE SETS OF FINGERPRINTS AS A MATCH ARE MADE BY THE GENERAL APPEARANCE OF THE PRINT AND ITS NUMBER OF MAJOR LINES. THESE LINES ARE CALLED ARCHES, LOOPS AND WHORLS.
JUDGING ARCHES, LOOPS AND WHORLS IS DIFFICULT WORK. COMPUTERS ARE USED FOR PART OF THE MATCHING. BUT EXPERTS MAKE THE FINAL JUDGMENTS. THESE EXPERT JUDGMENTS HAVE BEEN PROVEN RIGHT MILLIONS OF TIMES. AS ONE FORMER F-B-I OFFICIAL SAID, "AS FAR AS WE KNOW, THERE NEVER HAS BEEN A FALSE MATCH."SCIENTISTS NOW ARE ARGUING ABOUT A NEW POSSIBILITY IN FINGERPRINTING. THE IDEA IS THAT THE MATERIAL LEFT BY A PRINT ALSO MAY BE USED FOR IDENTIFICATION -- NOT JUST THE FINGERTIP LINES.
THE OILS FROM A PERSON'S BODY MAY BE LEFT IN A FINGERPRINT. SPECIAL DEVICES CAN FIND DRUGS AND SOME BODY CHEMICALS IN THIS MATERIAL. SOME OF THESE SUBSTANCES CAN BE IDENTIFIED.
((MUSIC BRIDGE))
FINGERPRINTS ARE INTERESTING NOT ONLY TO POLICE. IN RECENT YEARS, SCIENTISTS HAVE USED INFORMATION ABOUT FINGERPRINTS FOR THEIR STUDIES OF HUMAN DEVELOPMENT. THEIR STUDIES HAVE HELPED THEM FIND HOW PEOPLE IN SOUTH AMERICAN VILLAGES ARE RELATED. THE STUDIES HAVE HELPED THEM LEARN ABOUT HOW PEOPLE IN PAPUA NEW GUINEA HAVE MOVED AROUND.MEDICAL RESEARCHERS ALSO ARE INTERESTED IN FINGERPRINTS. MORE THAN SIXTY YEARS AGO, RESEARCHER HAROLD CUMMINS DESCRIBED UNUSUAL FINGERPRINT PATTERNS IN BABIES BORN WITH DOWN'S SYNDROME. THESE CHILDREN NEVER REACH THE SAME INTELLIGENCE LEVELS AS NORMAL CHILDREN. THEY ALSO HAVE PHYSICAL DIFFERENCES. BECAUSE OF DOCTOR CUMMINS'S WORK, SCIENTISTS NOW HAVE DESCRIBED FINGERPRINT DIFFERENCES IN PEOPLE BORN WITH OTHER MEDICAL PROBLEMS.
TODAY, RESEARCHERS ARE STUDYING THE RELATIONSHIP OF FINGERPRINTS TO DISEASES THAT AFFECT OLDER CHILDREN AND ADULTS. SOME DAY, FINGERPRINTS MAY PROVIDE SUCH INFORMATION. IT IS POSSIBLE THAT FAR IN THE FUTURE THEY MAY EVEN BE ABLE TO TELL IF A PERSON WILL SUFFER FROM A HEALTH PROBLEM IN LATER YEARS. SUCH INFORMATION COULD HELP THEM WORK TO AVOID SUCH PROBLEM SO THAT PEOPLE CAN LIVE HEALTHIER LIVES.
(THEME)TODAY'S SCIENCE IN THE NEWS WAS WRITTEN BY JERI WATSON. IT WAS PRODUCED BY GEORGE GROW. THIS IS SARAH LONG.AND THIS IS BOB DOUGHTY. JOIN US AGAIN NEXT WEEK AT THIS SAME TIME FOR MORE NEWS ABOUT SCIENCE, IN SPECIAL ENGLISH, ON THE VOICE OF AMERICA.