>> FINGERPRINTS, BLOOD TYPES.

THESE ARE SOME OF THE CLUES CRIME SCENE INVESTIGATORS LIKE THESE KIDS USE TO SOLVE A PUZZLE.

LEARN MORE ABOUT CSI, THE SCIENCE OF FORENSICS.

SCIENTISTS ARE STANDING BY TO ANSWER YOUR QUESTIONS.

STAY TUNED.

"D4K" IS NEXT.

>> HI, I'M JOAN CARTAN-HANSEN.

WELCOME TO "D4K."

WE'RE TALKING ABOUT CRIME SCENE INVESTIGATIONS, CSI AND FORENSIC SCIENCE.

BUT BEFORE WE GO TO THE STUDIO TO ANSWER YOUR QUESTIONS, LET'S FIND OUT MORE.

>> 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 SCENE 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 TIMES 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 4 THE IDAHO DEPARTMENT OF FISH AND 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 SCIENTISTS TOO.

THAT'S 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.

>> JOINING ME NOW TO ANSWER YOUR QUESTIONS ABOUT FORENSIC SCIENCE ARE MT., FORENSIC SERVICES QUALITY MANAGER, AND NATASHA WHEATLEY, LATENT FINGERPRINT, SHOE PRINT, AND TIRE TRACK EXAMINER, BOTH WITH IDAHO STATE POLICE.

FORENSIC SERVICES.

THANK YOU BOTH FOR BEING HERE.

AND OF COURSE WE WANT TO HEAR FROM YOU.

GIVE US A TALL, TOLL-FREE, AT 1-800-973-9800.

OR EMAIL US AT D4K@IDAHOPTV.ORG.

REMEMBER, WHEN YOU ?END A QUESTION, AND YOU YOUR CLASS WILL HAVE A CHANCE TO WIN DVDs AND OTHER PRIZES.

LET'S GO TO OUR FIRST QUESTION FROM KATE IN MRS.

SCHULTZ CLASS.

HOW DO YOU FIND FINGERPRINTS?

>> SO WE GET ITEMS OF EVIDENCE IN, OR WE GO OUT TO CRIME SCENES, AND THERE ARE DIFFERENT -- THE THING IS, FINGERPRINTS ARE COMPOSED OF DIFFERENT COMPONENTS.

THERE ARE ORGANIC CHEMICALS 90, THERE ARE ALSO DIFFERENT SUBSTRATES OR THINGS LIKE GREASE, AND THEN YOU TOUCH AND APPLY THOSE.

SO HOW WE FIND -- HOW WE FIND FINGERPRINTS IS WE USE DIFFERENT CHEMICALS OR POWDERS TO MAKE THESE -- >> MAKE THEM APPEAR.

>> EXACTLY.

THEY'VE DUSTED DOWN -- >> POWDER IS ONE WAY, IT'S A USEFUL WAY TO FIND FINGERPRINTS.

AND THEN CHEMICALS.

WE ACTUALLY DEVELOP MORE PRINTS WITH CHEMICALS THAN POWDERS.

>> DYLAN FROM MRS.

HUFFMAN'S CLASS WOULD LIKE TO KNOW IF YOU FOUND EVIDENCE LIKE A FINGERPRINT, HOW DO YOU KNOW WHO IT BELONGS TO?

>> SO FINGERPRINTS ARE VERY UNIQUE TO PEOPLE.

REASON BEING IS BECAUSE THERE'S A GENETIC COMPONENT TO IT.

YOUR FINGERPRINTS ARE OFTEN ONE OF YOUR PARENTS, BUT MORE IMPORTANTLY FINGERPRINTS DEVELOP WHEN YOU'RE DEVELOPING INSIDE YOUR MOM'S STOMACH.

AND SO THERE'S DIFFERENT FACTORS.

THIS IS THE THIRD TO FOURTH MONTH FETAL DEVELOPMENT IS WHEN THESE ARE DEVELOPING.

THERE'S DIFFERENT FACTORS DOING ON -- GOING O. DIFFERENT PRESSURES, SO AS FINGERPRINTS ARE DEVELOPING, WE CALL IT SECOND LEVEL OR DETAIL, YOU HAVE ENDING RIDGES AND WHATNOT IN YOUR FINGERPRINTS, AND THOSE -- THAT IS ABSOLUTELY WHAT MAKES IT UNIQUE TO A PERSON, THOSE ENDING RIDGES.

WE ALL HAVE PATTERN TYPES THAT MAY BE SIMILAR, THERE ARE THREE TYPES OF PATTERNS.

ARCHES, LOOPS, AND WHIRLS.

>> LET'S GET TO OUR FIRST CALLER.

ARE YOU THERE?

GO AHEAD.

>> Caller: I WAS WONDERING WHERE MOST CRIMES TAKE PLACE.

LIKE IN A PARKING LOT, OR SOMETHING LIKE THAT.

>> OK.

LET'S ASK MATTHEW.

>> THAT'S A VERY GOOD QUESTION.

THERE ARE CRIMES THAT HAPPEN IN PARKING LOTS.

USUALLY CARS BEING BROKEN INTO, AND THOSE KIND OF CRIMES THAT COULD BE SOLVED USING LATENT PRINT EXAMINATIONS THERE.

ARE CRIMES TAKING PLACE ALL OVER IN OUR CITIES, SOMETIMES IN HOMES, SOMETIMES OUTSIDE.

SO THAT'S A GOOD QUESTION, BECAUSE I CAN'T REALLY GIVE ADIRECT ANSWER WHERE ALL CRIMES TAKE PLACE, BECAUSE CRIMES HAPPEN ALL OVER.

>> WE HAVE SOME QUESTIONS ON TAPE.

FROM THE DISCOVERY CENTER, I THINK OUR FIRST ONE IS FROM PORTER.

>> MY NAME IS QUARTER, MY QUESTION IS, WHAT IS THE HARDEST EVIDENCE TO FIND AT A CRIME SCENE?

>> WHAT'S THE HARDEST EVIDENCE TO FIND?

>> PROBABLY THE HARDEST EVIDENCE TO FIND WOULD BE TRACE EVIDENCE.

WE'RE TALKING ABOUT HAIRS, FIBERS, THINGS LIKE THAT FROM MATERIAL.

ALSO VERY HARD EVIDENCE TO FIND ARE THINGS THAT YOU CAN'T SEE.

LIKE DNA EVIDENCE.

AND WE MAY TALK ABOUT DNA EVIDENCE IN A MINUTE, BUT THINGS YOU CAN'T SEE, LIKE A FINGERPRINT UNTIL IT'S DEVELOPED.

>> OK.

SPEAKING OF FINGERPRINTS, A QUESTION FROM TALON, WOULD LIKE TO KNOW IF YOU INVESTIGATED A CRIME AND FOUND ON A WALL SOMEONE'S FINGERPRINT, HOW WOULD YOU KNOW IF IT BELONGED TO THE CRIMINAL OR THE OWNER OF THE HOUSE?

>> WE LIKE TO COLLECT WHAT WE CALL ELIMINATION PRINTS FROM ANYBODY THAT COULD POSSIBLY HAVE TOUCHED THAT WALL.

SO THE OWNER OF THE HOUSE WE WOULD ACTUALLY COLLECT THEIR PRINTS, INK THEIR HANDS, TAKE THE PRINTS AND WE CAN DO A COMPARISON FROM THAT AND RULE THEM OUT AS THE SOURCE OF THE PRINT.

>> KATE WOULD LIKE TO KNOW FROM MRS.

HUDSON'S CLASS, IN BAD WEATHER LIKE SNOW, IT IS HARDER TO FIND CLUES?

>> SOMETIMES IT CAN BE.

IT CAN BE REALLY HARD TO FIND EVIDENCE IN THE SNOW IF THE EVIDENCE IS BURIED UNDER THE SNOW.

SOMETIMES SNOW MAKES IT EASIER TO FIND THE EVIDENCE BECAUSE IT MIGHT BE ON TOP OF THE SNOW.

IF YOU HAVE A LAYER OF SNOW AND THEN A SUSPECT WALKS ACROSS THE SNOW, YOU MAY GET VERY GOOD SHOE PRINTS, OR YOU MAY GET TIRE TRACK EVIDENCE FROM A BLANKET OF SNOW.

AND THAT EVIDENCE WOULD BE ON TOP OF THE SNOW.

>> LET'S GO TO OUR NEXT QUESTION FROM THE DISCOVERY CENTER.

I THINK IT'S QUINN.

LET'S FIND OUT.

>> MY NAME IS TATA AND I GO TO HAIR TAN MIDDLE SCHOOL, AND MY QUESTION IS, WOULD ONLY ONE DETECTIVE COLLECT THE EVIDENCE, OR MORE?

>> USUALLY THERE ARE MULTIPLE DETECTIVES, AND THERE ARE MULTIPLE CRIME SCENE RESPONDERS.

DETECTIVES ARE USUALLY SWORN POLICE OFFICERS.

THEY GO THROUGH SPECIAL TRAINING TO BE ABLE TO BECOME A POLICE OFFICER.

WE GO THROUGH SPECIAL TRAINING TO BE A FORENSIC INVESTIGATOR.

IT'S VERY DIFFICULT TRAINING, BECAUSE WE ARE MORE FOCUS ORDER THE SCIENCE BEHIND THE INVESTIGATION.

THE DETECTIVES ARE MORE INTERESTED IN THE SUSPECTS AND THE INVESTIGATION.

AND SO WE LOOK MORE FOR THE CLUES THAT THE SCIENTIFIC CLUES AND TRY AND COLLECT THOSE CLUES FOR THE DETECTIVES.

>> EMMA WOULD LIKE TO KNOW, IS IT POSSIBLE TO FIND OUT IF A THIEF IS A BOY OR A GIRL?

>> THAT IS POSSIBLE.

IN FACT, THAT IS WHAT DNA SCIENCE IS ALL ABOUT.

THERE ARE SPECIFIC AREAS ON YOUR DNA THAT MAKE YOU MALE OR FEMALE.

AND SO WHEN WE RUN A DNA TEST, WE LOOK TO SEE IF THE SUSPECT IS MALE OR FEMALE.

AND THAT'S A VERY IMPORTANT PART OF THE INVESTIGATION.

>> LET'S GO TO OUR NEXT CALLER, THAT'S MADDY IN EAGLE.

GO AHEAD.

>> HOW CAN YOU FIND DIFFERENT PEOPLE FINGERPRINTS WHEN THERE'S ONLY A COUPLE OF DIFFERENT PATTERNS, LIKE THE EYE SHAPE?

>> AS I SAID BEFORE, THERE WAS A THREE PATTERN TYPES, BUT WITHIN THOSE PATTERN TYPES IF YOU WILL LOOK AT YOUR FINGERS, YOU HAVE ENDING RIDGES, AND WHAT WE CALL BY IF YOU'RE INDICATIONS, WHICH IS BASICALLY A FORK IN THE ROAD.

IF YOU FOLLOW A BRIDGE AND ALL AFTER SUDDEN IT FORKS A RIDGE A RIDGE, WHAT -- THOSE ARE WHAT MAKE IT UNIQUE.

SO WE CAN IDENTIFY THOSE CHARACTERISTICS.

>> LAUREN WOULD LIKE TO KNOW, HOW MANY DIFFERENT TYPES OF DNA ARE THERE?

>> WELL, DNA IS MADE UP OF SEVERAL BASES.

SEVERAL CHEMICALS.

AND THOSE BASES CAN BE ORGANIZED INTO A NUMBER OF DIFFERENT WAYS.

EVERY PERSON'S DNA IS UNIQUE.

SO EACH PERSON WOULD HAVE A DIFFERENT DNA PROFILE, AND SO WE LOOK FOR THOSE DIFFERENCES WHEN WE'RE LOOKING TO SOLVE A CRIME.

>> THIS COMES FROM JAMIE, WHO IS HOME SCHOOLED.

THE QUESTION IS, WHAT EDUCATION IS REQUIRED FOR A CAREER IN FORENSICS.

WHAT ADVICE WOULD YOU GIVE TO A 10, 12, 13-YEAR-OLD WHO IS INTERESTED IN THIS GOING INTO THIS WHEN THEY GROW UP?

>> WELL, SPECIFICALLY DEPENDING ON WHAT TYPE OF FORENSICS YOU WANT TO BE IN, THERE'S DIFFERENT DISCIPLINES THAT WE HAVE.

WE HAVE CHEMISTRY, BIOLOGY, I'M IN LATENT, SO HARD SCIENCE IS RECOMMENDED, HARD SCIENCE BEING CHEMISTRY, BIOLOGY, PHYSICS, THAT SORT OF THING.

I HAVE A DEGREE IN CHEMISTRY, SO I ADVOCATE THAT.

BUT -- [LAUGHTER] >> I HAVE A DEGREE IN BIOLOGY, AND AT THE STATE CRIME LAB HERE IN IDAHO, WE ONLY HIRE PEOPLE WITH SCIENTIFIC DEGREES.

THEY HAVE TO HAVE A FOUR-YEAR DEGREE FROM A UNIVERSITY OR FROM A COLLEGE TO BE ABLE TO WORK FOR US AT OUR CRIME LAB.

THERE ARE OTHER LABS, INCLUDING POLICE LABS, WHERE A HIGH SCHOOL DEGREE WOULD BE ENOUGH FOR YOU TO BE ABLE TO WORK IN THEIR CRIME SCENE UNIT.

>> MOLLY, CARSON, TAYLOR, AND ALEC HAVE THE SAME QUESTION, DO TWINS HAVE THE SAME FINGERPRINTS?

>> THEY DO NOT.

AND THE REASON BEING, WHEN THEY'RE DEVELOPING BEFORE BIRTH, THERE'S DIFFERENT PRESSURES GOING ON, THEY CALL THIS DIFFERENTIAL GROWTH.

YOU HAVE DIFFERENT THINGS GOING ON, SO -- >> EVEN IDENTICAL TWINS?

>> YEAH, IDENTICAL TWINS -- AND I'VE SEEN IDENTICAL TWINS WHERE THEY WERE VERY CLOSE, HAD THE SAME PATTERN TYPES ON EVERY SINGLE FINGER, BUT YOU GET DOWN THERE AND YOU LOOK AT THE SMALL DETAILS IN THERE, AND THEY'RE DIFFERENT.

>> TROY WOULD LIKE TO KNOW, DO YOU USE SPECIAL CAMERAS IN YOUR WORK?

>> WE DO.

WE USE VERY EXPENSIVE CAMERAS.

USUALLY THEY'RE NOT THE ONES THAT ARE THE POINT-AND-SHOOT TYPE CAMERAS YOU WOULD SEE YOUR MOM AND DAD USING OR YOU MIGHT HAVE ON A CELL PHONE,UT THE CAMERAS WE USE ARE VERY HIGH-END, VERY EXPENSIVE CAMERAS, AND THEY SOMETIMES CAN COME WITH SPECIAL FILTERS SO IT ALLOWS US TO VIEW BLOOD ON A DARK CLOTHING ITEM, AND THOSE WE WOULD CALL UVIR FILTERS.

WE HAVE VERY, VERY NICE CAMERAS THAT WE WORK WITH.

>> LET'S GO TO HEIDI.

>> Caller: HI.

I WAS WONDERING, WHAT CREATES A PATTERN ON THE BULLET?

>> OK.

>> I WOULD SAY THAT NEITHER ONE OF US ARE BALLISTICS EXPERTS, BUT WE HAVE HAD TRAINING IN BALLISTICS, AND SO I WON'T GET TOO DETAILED FOR YOU, BUT BASICALLY THE MACHINING OF THE BARREL OF A WEAPON CREATES A PEA TURN IN THE INSIDE OF THAT BARREL.

WHEN A BULLET IS FIRED OUT OF THAT, THAT WEAPON, YOU'LL GET CERTAIN RIFLING CHARACTERISTICS MADE INTO THE BULLET, BECAUSE THAT'S A SOFTER METAL THAN THE BARREL, AND THOSE -- THAT PATTERN THAT GOES INTO THE BULLET THEN WILL BE ABLE TO BE VIEWED UNDER A MICROSCOPE BY A FORENSIC SCIENTIST.

THERE'S ALSO SOME OTHER THINGS ON A GUN THAT WILL MAKE A MARK, LIKE ON A CONSIDER TOM RIDGE CASE IF THAT STAYS IN THE WEAPON OR IF IT'S EJECTED FROM THE WEAPON.

YOU'LL SEE MARKS FROM AN EJECTOR FROM AN EXTRACTOR, AND ALSO FROM THE BREACH BASE WHERE IT CONTACTS THE WEAPON BEFORE IT'S FIRED.

>> LET'S GO TO ANDREW IN TWIN FALLS.

ANDREW?

>> Caller: HI.

I HAVE A QUESTION.

>> GO AHEAD.

>> Caller: -- TO IDENTIFY FINGERPRINTS ON ANY SURFACE?

>> WHAT CHEMICALS DO YOU USE TO IDENTIFY FINGERPRINTS?

>> SO ON PAPER, WE CAN DEVELOP REALLY GOOD FINGERPRINTS, AND OUR MAIN CHEMICAL WE USE PAPER IS CALLED NENHYDREN.

IT DEVELOPS THE FROA TEEN -- PROTEIN IN THE FINGERPRINTS.

WE USE OTHER CHEMICALS THAT REACT WITH BLOOD, THERE -- WE HAVE QUITE A FEW CHEMICALS.

>> WE'VE GOT A QUESTION, ANOTHER QUESTION FROM THE DISCOVERY CENTER.

LET'S GO AHEAD AND TAKE A LOOK AT IT, SEE WHAT THE QUESTION IS.

>> MY NAME IS HANNAH, I GO TO AMITY ELEMENTARY SCHOOL, AND MY QUESTION IS, WHAT DOES RYBO STAND FOR AND NUKE LICK ACID?

>> ANNA IS CAUSING US TO GO BACK TO OUR BIOLOGY CLASSES.

RYBOS IS A SUGAR.

THE SUGAR ON THE BACKBONE OF THE DNA.

THE DNAS MADE UP OF SEVERAL DIFFERENT TYPES OF MOLECULES, AND THE SUGAR BACKBONE -- PHOSPHATE BACKBONE IS PART OF THAT, BUT THEN THE SUGAR IS ALSO WHAT MAKES PART OF THAT MOLECULE.

>> KATELYN IN DALTON ELEMENTARY WOULD LIKE TO KNOW HOW MANY DIFFERENT TYPES OF DNA SAMPLES CAN DETECTIVES ANALYZE FROM A CRIME SCENE?

WHAT ARE YOU LOOKING FOR?

>> WHAT WE'RE LOOKING FOR IS ANYTHING THAT COMES FROM A BODY.

DNA IS IN ANY CELL, ALMOST ANY CELL IN YOUR BODY.

TISSUES, SKIN CELLS, HAIR, BLOOD, THERE'S A LOT OF DIFFERENT PLACES WHERE YOU WOULD FIND CELLS.

AND SO DNA IS THE SAME IN ANY PERSON, WHETHER I TAKE A SKIN CELL OR A BLOOD, YOUR DNA WOULD BE THE SAME IN ALL OF THOSE DIFFERENT TYPES OF SAMPLES.

>> LET'S GO TO ETHAN IN BOISE.

ETHAN?

>> Caller: I WAS WONDERING WHAT -- WHAT THE BEST WAY IS TO -- >> TRY THAT AGAIN.

>> Caller: I WAS WONDERING TO KNOW THE BEST WAY TO NARROW DOWN THE SUBSTANCE.

>> I MISSED -- >> THE BEST WAY TO NARROW DOWN SUSPECTS.

WHAT SORT OF EVIDENCE DO YOU COLLECT TO SEPARATE THE INNOCENT AND GUILTY?

>> I THINK DETECTIVES WOULD DO THIS A LOT, NARROW DOWN THE SUSPECT LIST BY GOING OUT AND TALKING TO THEM.

AND THEN THEY GENERATE A LIST POSSIBLY TO DO FINGERPRINT COMPARISONS OR DNA.

BUT THEY TEND TO NARROW DOWN THE SUSPECT LIST BEFORE WE GET -- >> BRYAN FISCHER YOU GET THEM.

>> SOMETIMES IF THEY DON'T KNOW WHO THE SUSPECT IS, WE WILL RUN IT AGAINST DATABASES OF KNOWN INDIVIDUALS THAT WE HAVE, LIKE IN DNA, WE HAVE PEOPLE THAT HAVE SUBMITTED THEIR DNA ACCEPT ALSO AND WE'LL COMPARE THE EVIDENCE AGAINST THOSE DATABASES.

SOMETIMES THE DETECTIVES WILL SEND US SAMPLES THAT THEY WANT US TO LOOK AT IN ORDER TO NARROW DOWN THE NUMBER OF SUSPECTS THAT THEY'RE LOOKING AT.

>> BRIANNA WOULD LIKE TO KNOW, HOW OLD WERE YOU WHEN YOU KNEW YOU WANTED TO WORK IN CRIME SCENE INVESTIGATION?

>> I WAS IN COLLEGE BEFORE I REALIZED THAT I COULD WORK IN FORENSIC SCIENCE.

THAT'S REALLY WHEN I BECAME INTERESTED IN FORENSICS.

>> THAT'S THE SAME WITH ME, I WAS GETTING A CHEMISTRY DEGREE AND REALIZED IT COULD BE APPLIED TO FORENSICS.

>> WHAT KIND OF CLASSES AGAIN WOULD YOU SUGGEST PEOPLE TAKE IF THEY'RE INTERESTED IN BECOMING A FORENSIC SCIENTIST?

>> LOTS OF BIOLOGY, LOTS OF CHEMISTRY, PHYSICS, ALL THE SCIENCE CLASSES ARE VERY IMPORTANT WHEN IT COMES TO THIS JOB, BECAUSE YOU HAVE TO UNDERSTAND A LOT OF THE SCIENTIFIC PRINCIPLES IN ORDER TO UNDERSTAND THAT THE THINGS YOU'RE DOING IN YOUR JOB.

>> SHAUNA WOULD LIKE TO KNOW IF TWO FINGERPRINTS ARE MIXED, HOW DO YOU SEPARATE THEM?

>> WE DON'T HAVE -- I'M TAKING THAT THIS AS, THEY'RE ON TOP OF EACH OTHER.

WE HAVE NO WAY TO SEPARATE THE FINGERPRINTS.

BUT THAT BEING SAID, WE DON'T NEED A LARGE AREA IF IT'S A GOOD, CLEAR QUALITY TO MAKE AN IDENTIFICATION.

IT DEPENDS ON THE EXPRIPT WHAT'S AVAILABLE.

>> ILLEGAL IMMIGRATIONIE FROM MRS.

WOODALL'S CLASS WOULD LIKE TO KNOW, WHY CAN'T EVIDENCE TOUCH OTHER EVIDENCE?

WHAT IS CROSS CONTAMINATION?

WHAT IS THAT?

>> THIS GOES BACK TO A PRINCIPLE CALLED LOW CARTS PRINCIPLE.

IT'S A BASIC PRINCIPLE IN FORENSIC SCIENCE.

THAT'S ARE FOR TWO ITEMS ARE IN CONTACT WITH EACH OTHER, THEY WILL TRANSFER EVIDENCE OR TRANSFER THINGS BACK AND FORTH BETWEEN EACH OTHER.

SO WHEN AN ITEM IS IN CLOSE CONTACT, IT MIGHT CONTAMINATE THE OTHER THING, AND THEN WE HAVE TO LOOK FOR -- IT'S REALLY THE BASICS OF FORENSICS.

WE'RE LOOKING FOR EVIDENCE OF THAT TRANSFER.

>> ELIZABETH ASKS, WHAT DO YOU DO AT YOUR JOB?

TELL US ABOUT WHAT YOU DO, NATASHA.

>> MY JOB, I OBVIOUSLY DO LAY TONIGHT COMPARISONS, WHICH IS A SUED BY SIDE ANALYSIS, BUT I ALSO DO LATENT PRINT PROCESSING.

SO DETECTIVES OR POLICE OFFICERS WILL GATHER EVIDENCE IN, AND THEY WILL SEND IT IN, AND I GO THROUGH STEP BY STEP PROCESSING DEPENDING ON WHAT THE ITEM IS MADE OF TO TRY TO FIND -- WE CALL THESE LATENT PRINTS, AND LATENT JUST MEANS HIDDEN.

SO I TRY TO MAKE THEM SEEN.

>> SO DOES EVERYTHING HAVE FINGERPRINTS?

OBVIOUSLY YOU THINK OF -- WE SHOWED THE POP CAN HAS FINGERPRINTS, BUT PAPER, GLASS?

>> PAPER, GLASS, AND SKIN -- >> SKIN?

>> WELL, YES YOU CAN, THERE HAVE BEEN CASES, BUT THE THING IS, FINGERPRINTS ARE VERY FRAGILE, DEPENDING ON WHAT -- ON PAPER THEY'RE PRETTY STABLE, SO WE CAN GET FINGERPRINTS OFF OF THAT PRETTY GOOD.

BUT LIKE IF I TOUCH THIS GLASS, I'M GOING TO LEAVE FINGERPRINTS DEPENDING ON WHAT I HAVE ON MY HANDS.

IF I HAVE LOTION I'M GOING TO LEAVE GOOD FINGERPRINTS, BUT AND THEN I CAN GO BACK THROUGH AND PROCESS THOSE, BUT IF SOMEBODY TOUCHES THEM OR WIPES ACROSS THEM THEY'LL DESTROY THE PRINTS.

SO THEY'RE PRETTY FRAGILE.

>> LET'S GO TO OUR NEXT CALLER, AVA IN -- AT HIDDEN SPRINGS ELEMENTARY.

GO AHEAD.

>> Caller: HELLO?

>> HI.

GO AHEAD.

>> Caller: I'M AVA, AND MY QUESTION IS, IS IT HARD TO FIND SUSPECTS' FINGERPRINTS IN THE RAIN?

>> WHAT A GOOD QUESTION.

>> THAT IS A VERY GOOD QUESTION.

ACTUALLY, WE CAN DEVELOP FINGERPRINTS IN WATER OR ITEMS THAT HAVE BEEN IN WATER, OR IN RAIN.

THERE'S -- I DON'T WANT TO GET THE CHEMICAL WRONG.

FPR IS WHAT IT IS.

I CAN'T REMEMBER WHAT THAT STAND FOR, I'M SORRY.

>> THAT'S OK.

YOU CAN GET -- SO HOW DOES WEATHER AFFECT HOW YOU COLLECT EVIDENCE?

>> WEATHER CAN BE VERY DIFFICULT FOR US, AND IN AN INVESTIGATION, FOR EXAMPLE F. WE'RE PROCESSING A DIRT ROAD, AND IT STARTS TO RAIN, THE RAIN CAN WASH AWAY CRITICAL EVIDENCE SUCH AS SHOE PRINTS, AND TIRE TRACKS.

IF THERE'S BLOOD AND WE'RE PROCESSING A SCENE OUTSIDE, IT MAY WASH AWAY THE BLOOD, OR IT MAY DILUTE THE BLOOD SO THAT WE CAN'T COLLECT IT OR FIND IT.

SO WEATHER CAN BE A BIG PROBLEM WITH EVIDENCE.

>> CAN YOU SPRAIN TO ME ABOUT TIRE TRACKS?

HOW YOU COLLECT TIRE TRACKS AS EVIDENCE?

>> TIRE TRACKS, THE MAIN METHOD TO COLLECT IT IS -- THE BEST IS TO PHOTOGRAPH WITH A SCALE.

AND THEN AFTER THAT, HAVING GOOD QUALITY PHOTOGRAPHS, THEN WE CAN DO CASTS OF THEM, AND WE WANT TO MAKE SURE WE DO A CAST LONG ENOUGH TO DO A FULL ROTATION OF WHAT A TIRE WOULD BE.

>> ARE TIRES UNIQUE ENOUGH THAT THEY CAN BE USED AS EVIDENCE?

>> YES, THEY CAN BE.

THE REASON BEING, TIRES RANDOMLY PICK UP ROCKS, OR GET CUT IN CERTAIN AREAS, AND WE CAN USE THIS TO IDENTIFY A SPECIFIC TIRE.

>> GREAT.

LUKE WOULD LIKE TO KNOW IF A MURDERER OR KIDNAPPER GETS HURT IN THE PROCESS OF A CRIME, AND THEY BLEED, WILL THE POLICE BE ABLE TO USE THEIR DNA?

>> ABSOLUTELY.

THAT'S ONE OF THE EASIEST WAYS TO FIND A CRIMINAL, OR TO FIND A SUSPECT, IS IF THEY LEAVE SOMETHING OF THEIRS AT THE SCENE, INCLUDING BLOOD OR WHAT WOULD BE DNA FROM THEIR BLOOD.

SO IF THEY LEAVE BLOOD AT THE SCENE, WHAT WE WILL DO IS WE WILL THEN TAKE THAT BLOOD BACK TO THE LAB, WE'LL PROCESS IT, AND DEVELOP THEIR DNA PROFILE, AND THEN WE WILL COMPARE IT AGAINST DATABASES OR COMPARE IT AGAINST SUSPECTS THAT THE DETECTIVES SAY MIGHT BE INVOLVED IN THE CASE.

>> EMMA WOULD LIKE TO KNOW, DO YOU WORK WITH EVIDENCE RIGHT AT THE CRIME SCENE, OR DO YOU WORK IN A LAB?

>> BOTH, ACTUALLY.

WE GO OUT TO CRIME SCENES, DEPENDING ON IF AGENCIES CALL US, AND WE CAN -- I'VE BEEN OUT TO MANY CRIME SCENES WHERE WE PROCESS LATENT PRINTS, HIDDEN FINGERPRINTS RIGHT THERE AT THE SCENE.

>> IS THERE ONE MORE LIKELY TO BE IN THE LAB, OR ONE LESS LIKELY TO BE IN THE LAB?

>> DEPENDING ON THE SIZE OF THE ITEM, SO, YOU KNOW, HOUSES WILL OBVIOUSLY GO OUT TO THE SCENE, BUT THEN WE LIKE TO COLLECT SMALLER ITEMS, LIKE IF THERE WAS A CUP THERE, WE WOULD HAVE THAT SENT IN SO WE COULD USE CHEMICALS TO PROCESS THAT.

>> COULD YOU EXPLAIN HOW YOU FIND DNA?

OR PUT SOMEONE'S DNA TOGETHER?

>> SOMETIMES WE CAN FIND IT BECAUSE WE CAN SEE THE BODY FLUID.

LIKE BLOOD.

WE WOULD BE ABLE TO SEE THAT IF IT WERE ON A COUNTER TOP OR ON A FLOOR OR SOMETHING LIKE THAT.

WE WOULD BE ABLE TO COLLECT IT VERY EASILY.

OTHER TIMES IF IT'S SOMETHING THAT A SUSPECT MIGHT HAVE TOUCHED, WE WON'T NECESSARILY BE ABLE TO SEE THEIR SKIN CELLS THAT MIGHT HAVE BEEN DEPOSITED ON THAT ITEM.

SO IN THOSE CASES, WE MIGHT ASK A LATENT PRINT EXAMINER TO DEVELOP THE LATENT PRINT FIRST, AND WE WOULD PHOTOGRAPH IT, AND THEN WE COULD SWAB THAT AREA AND THAT WAY WE CAN TAKE THE CELLS AND DO THE DNA PROCESSING ON THOSE CELLS.

>> COULD YOU DESCRIBE A LITTLE BIT HOW YOU PROCESS DNA, TO READ IT TO SEPARATE OUT -- >> IT'S A VERY COMPLEX PROCESS.

WHAT WE BASICALLY DO IS WE TAKE THE DNA, WHICH IS IN THE NUCLEUS OF THE CELL, IN THE MIDDLE OF THE CELL, AND WE BREAK UP THE WHOLE CELL AND WE ONLY LOOK AT THE DNA.

ONCE WE HAVE THAT DNA, THEN WHAT WE WILL DO IS WE USE ALMOST LIKE A XEROX MACHINE, LIKE A COPIER, AND WE MAKE MANY, MANY, MANY COPIES OF THE DNA.

AND WE ATTACH A LITTLE FLUORESCENT OR A LITTLE COLORED MARKER ON IT, AND THAT COLORED MARKER WE RUN ON A MACHINE, AND IT WILL -- IT BASICALLY SEPARATES THE MACHINE SEPARATES IT BY SIZE.

IT'S KIND OF LIKE IF YOU TOOK A B.W.

OR SOMETHING SMALL AND PULLED IT THROUGH JELL-O, THAT'S WHAT WE DO ON THIS INSTRUMENT.

THE SMALLER THINGS WILL GO THROUGH THE JELL-O FAST, BIG THINGS GO THROUGH THE JELL-O SLOW.

SO WE CAN SEPARATE IT BY SIZE, AND THAT WAY WE CAN LOOK AT THE DNA PROFILE.

>> FROM ASHLEY, IS IT EASY, IS YOUR JOB EASY?

>> NO, AND IT TAKES -- TO BE A LATENT EXAMINER IT TAKES ABOUT TWO YEARS OF TRAINING TO GO THROUGH.

I WOULD SAY NO.

>> THE QUESTION IS, IS YOUR JOB FUN?

>> ABSOLUTELY.

WE HAVE VERY, VERY GOOD TIMES AT OUR JOB.

IT'S FUN TO GO OUT AND COLLECT EVIDENCE OF COURSE IT'S FUN TO SEE WHAT HAPPENS AS A RESULT OF YOUR EXAMINATION, AND IT'S FUN TO HELP PEOPLE.

THAT'S WHAT I LIKE ABOUT MY JOB.

WE ARE HELPING PEOPLE TO BE ABLE TO SOLVE CRIMES.

>> AND WHAT WAS THE FIRST CRIME YOU EVER SOLVED?

>> I DON'T THINK WE SO MUCH SOLVE CRIMES.

I THINK I GIVE ASSISTANCE TO SOLVE CRIMES.

SO A LOT OF TIMES I DON'T EVEN KNOW IF I MAKE AN IDENTIFICATION, I DON'T KNOW WHAT HAPPENS WITH IT AFTER THAT UNLESS I TESTIFY IN COURT.

SO I LIKE TO THINK OF ASSISTING IN THE CRIME SOLVING.

>> ON THAT, I THINK WE'VE RUN OUT OF TIME.

THANK YOU VERY MUCH.

I APPRECIATE, MATTHEW AND NATASHA FOR JOINING US TODAY.

AND THANK YOU FOR BEING HERE.

IF YOU WANT TO LEARN MORE ABOUT THIS TOPIC, GO FOR THE "D4K" WEBSITE.

CHECK OUT THE WEB-ONLY SHOW AND EXPLORE MORE INFORMATION ABOUT FORENSIC SCIENCE AND MANY OF THE TOPICS.

CHECK IT OUT AT IDAHOPTV.ORG.

CLICK ON "D4K."

LAST MONTH'S WINNER OF OUR QUESTION CONTEST WAS DAVID IN MRS.

WOODALL AS CLASS.

CONGRATULATIONS.

REMEMBER, WHEN YOU SEND US A QUESTION, YOU AND YOUR CLASS ARE ELIGIBLE FOR OUR CONTEST.

YOU CAN WIN PRIZES, JUST BY SENDING IN A QUESTION.

NEXT MONTH, WE'LL BE TAKING YOUR QUESTIONS ABOUT OWLS.

AND WE'RE GOING TO TUNE IN A WEEK EARLIER THAN USUAL, BECAUSE OF THE HOLIDAYS.

WE'LL BE ON DECEMBER 14th.

SAME TIME, THOUGH, 2:00 P.M.

MOUNTAIN, 1:00 P.M.

PACIFIC.

YOU CAN ALWAYS WATCH OUR ARCHIVED VERSION AT IDAHOPTV.ORG IDAHOPTV.ORG/D4K.

>>> THANKS FOR JOINING US.

WE'LL SEE YOU NEXT TIME ON "D4K."

Captioning performed by LNS Captioning www.LNScaptioning.com