JOAN CARTAN-HANSEN, HOST:

FINGER PRINTS, BLOOD TYPES,

THESE ARE SOME OF THE CLUES

CRIME SCENE INVESTIGATORS USE

TO SOLVE A PUZZLE.

LEARN MORE ABOUT CSI, THE

SCIENCE OF FORENSICS.

(MUSIC)

IT WAS A COLD WINTER

NIGHT, BUT WHEN I WALKED INTO

THE ROOM, I STARTED TO SWEAT.

THIS IS THE SCENE OF THE

CRIME, AND I NEEDED HELP TO

FIND OUT WHO TRASHED THIS

CLASSROOM.

>> IF YOU WANT TO SOLVE THE

CRIME, WHY DON'T YOU TRY

SCIENCE?

CRIME INVESTIGATORS USE TOOLS

AND SKILLS KNOWN AS FORENSIC

SCIENCE TO ANALYZE THE

EVIDENCE LEFT BEHIND.

IT HELPS THEM FIND OUT WHAT

HAPPENED AND MAYBE WHO

COMMITTED THE CRIME.

IN EARLIER TIMES, PEOPLE

THOUGHT THEY COULD DECIDE IF

SOMEONE WAS GUILTY JUST BY THE

WAY THEY ACTED.

THAT MEANT SOMETIMES INNOCENT

PEOPLE WERE CONVICTED OF

CRIMES.

THERE NEEDED TO BE A WAY TO

FIND RELIABLE EVIDENCE TO

CLEARLY IDENTIFY WHO WAS

GUILTY.

THAT'S HOW FORENSIC SCIENCE

AND CRIME SCENE INVESTIGATION

STARTED.

INVESTIGATORS LOOK AT EVIDENCE

FROM CRIME SCENES VERY

CAREFULLY.

EVIDENCE CAN BE SOMETHING LIKE

SOIL, OR A PLANT.

FOOTPRINTS.

TIRE TRACKS.

FIBERS.

AND BULLETS.

SOME EVIDENCE, LIKE

FINGERPRINTS, CAN BE VERY

USEFUL.

EVERY HUMAN BEINGS'

FINGERPRINTS ARE UNIQUE.

IF INVESTIGATORS FIND

FINGERPRINTS, THEY CAN COMPARE

THEM TO OTHER FINGERPRINTS

THEY HAVE ALREADY IDENTIFIED

AND SEE IF THERE'S A MATCH.

BLOOD AND OTHER BODY PRODUCTS

CAN ALSO BE TRACED TO THEIR

SOURCE.

THEY CONTAIN DNA.

DNA IS IN EACH CELL OF OUR

BODY AND IT'S MADE UP OF FOUR

TYPES OF CHEMICALS.

SCIENTISTS USE FOUR LETTERS,

A, G, C, AND T, TO DESCRIBE

THOSE CHEMICALS.

THEY USE COMPLEX INSTRUMENTS

TO TAKE THE DNA OUT OF THE

CELLS, MARK IT WITH

FLUORESCENT COLOR, AND PUT IT

INTO A COMPUTER TO BE READ.

WHEN THEY LOOK AT THE DNA,

SCIENTISTS SEE THE LETTERS

REPEATING IN CERTAIN PATTERNS.

IF THE DNA PATTERNS IN SAMPLES

FOUND AT THE CRIME SCENE MATCH

THE DNA PATTERN TAKEN FROM A

PERSON, THEN SCIENTISTS CAN

TIE THAT PERSON TO THE CRIME

SCENE.

NOT ALL FORENSIC SCIENTISTS

WORK ON HUMAN CRIMES.

SOME INVESTIGATORS WORK FOR

THE IDAHO DEPARTMENT OF FISH &

GAME.

THEY HELP SOLVE CRIMES LIKE

POACHING OR HELP BIOLOGISTS

FIND OUT EXACTLY WHAT KIND OF

SPECIES AN ANIMAL IS.

OTHER FORENSIC SCIENTISTS

STUDY DINOSAUR BONES TO LEARN

HOW THE CREATURES LIVE.

OR STUDY THE REMAINS OF

ANCIENT PEOPLE TO LEARN MORE

ABOUT THEIR CULTURE.

THESE SCIENTISTS ARE TRYING TO

LEARN HOW KING TUT, THE

ANCIENT EGYPTIAN RULER, DIED.

YOU CAN LEARN TO BE A FORENSIC

SCIENTIST TOO.

THESE STUDENTS ARE TAKING A

FORENSIC SCIENCE CLASS AT THE

DISCOVERY CENTER OF IDAHO.

>> WE CAN USE FORENSIC SCIENCE

TO FIND OUT WHO MADE THIS

MESS?

>> POSSIBLY.

BUT IT TAKES TRAINING TO LEARN

HOW TO COLLECT EVIDENCE AND

MAKE SURE IT'S NOT

CONTAMINATED.

>> OK, LET'S GO LEARN MORE

ABOUT THIS FORENSIC SCIENCE.

WHOEVER COMMITTED THIS CRIME

MUST BE REALLY SMART.CARTAN-HANSEN: IF YOU
WANT TO

LEARN MORE ABOUT FORENSIC

SCIENCE VISIT THE SCIENCE TREK

WEBSITE, YOU'LL FIND IT AT

SCIENCE TREK DOT ORG.

(MUSIC)

ANNOUNCER:

PRESENTATION OF SCIENCE TREK

ON IDAHO PUBLIC TELEVISION IS

MADE POSSIBLE THROUGH THE

GENEROUS SUPPORT OF THE LAURA

MOORE CUNNINGHAM FOUNDATION,

COMMITTED TO FULLFILLING THE

MOORE AND BETTIS FAMILY LEGACY

OF BUILDING THE GREAT STATE OF

IDAHO.

BY THE IDAHO NATIONAL

LABORATORY, MENTORING TALENT

AND FINDING SOLUTIONS FOR

ENERGY AND SECURITY

CHALLENGES, BY THE FRIENDS OF

IDAHO PUBLIC TELEVISION AND

THE CORPORATION FOR PUBLIC