Date: 1-16-01
SCIENCE IN THE NEWS #2107 - FINGERPRINTS
By JERI WATSONVOICE ONE:
THIS IS SARAH LONG.
VOICE TWO:
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.
((THEME))
VOICE ONE:
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.
VOICE TWO:
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.
VOICE ONE:
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.
VOICE TWO:
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.
VOICE ONE:
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.
VOICE TWO:
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.
VOICE ONE:
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.
VOICE TWO:
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.
VOICE ONE:
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.
VOICE TWO:
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.
VOICE ONE:
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."
VOICE TWO:
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))
VOICE ONE
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.
VOICE TWO:
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)
VOICE ONE:
TODAY'S SCIENCE IN THE NEWS WAS WRITTEN BY JERI WATSON. IT WAS
PRODUCED BY GEORGE GROW. THIS IS SARAH LONG.
VOICE TWO:
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.
Source: www.voa.gov/special/