Forensic ScienceForensic Science

Scientific MethodScientific Method

Observe the ProblemObserve the Problem Ask a QuestionAsk a Question Collect data, make observations, take Collect data, make observations, take

measurementsmeasurements Form a HypothesisForm a Hypothesis

Make observations and collect dataMake observations and collect data Hypothesis – a statement that explains Hypothesis – a statement that explains

observations that can be testedobservations that can be tested Is supported or refuted, never proven to be Is supported or refuted, never proven to be

true beyond all doubt.true beyond all doubt.

Scientific MethodScientific Method

Test your HypothesisTest your Hypothesis Experimenting – process of testing a Experimenting – process of testing a

hypothesis by gathering data under hypothesis by gathering data under controlled conditionscontrolled conditions

Compare control group to an experimental Compare control group to an experimental groupgroup

Independent Variable – experimentally Independent Variable – experimentally manipulated variablemanipulated variable

Dependent Variable – the responding variable in Dependent Variable – the responding variable in the experimentthe experiment

Scientific MethodScientific Method

Record and Analyze DataRecord and Analyze Data Form a ConclusionForm a Conclusion

Support or RefuteSupport or Refute

Forensic ScienceForensic Science

Forensic ScienceForensic Science Application of scientific methods to Application of scientific methods to

solving legal problems.solving legal problems.

Forensic ScienceForensic Science

Collecting Physical EvidenceCollecting Physical Evidence Physical EvidencePhysical Evidence

Tangible things left at crime sceneTangible things left at crime scene

Evidence FactorEvidence Factor Importance to Importance to CourtCourt

Where evidence is foundWhere evidence is found May have been plantedMay have been planted

Time it is foundTime it is found May have been there before May have been there before crimecrime

Way it is gatheredWay it is gathered Could be contaminatedCould be contaminated

Way it is removed from crime Way it is removed from crime scenescene

Incorrectly labeled could be Incorrectly labeled could be confused with other casesconfused with other cases

How it is documented and How it is documented and preservedpreserved

If stored incorrectly, it could be If stored incorrectly, it could be contaminated and uselesscontaminated and useless

Forensic ScienceForensic Science

Crime Scene ProceduresCrime Scene Procedures All witnesses located and identifiedAll witnesses located and identified Crime scene is securedCrime scene is secured

No evidence removed or movedNo evidence removed or moved No evidence tampered with or alteredNo evidence tampered with or altered No evidence is lostNo evidence is lost Non-evidence kept away from sceneNon-evidence kept away from scene

All evidence is identifiedAll evidence is identified Fingerprints, footprints, tiremarks are Fingerprints, footprints, tiremarks are

preserved for later usepreserved for later use

Forensic ScienceForensic Science

Crime Scene ProceduresCrime Scene Procedures Evidence is found and location is Evidence is found and location is

documenteddocumented Lift evidence without contaminatingLift evidence without contaminating Mark container w/location, date, time, Mark container w/location, date, time,

and nameand name Turn evidence to proper areaTurn evidence to proper area

Forensic ScienceForensic Science

Finding Trace EvidenceFinding Trace Evidence Fingerprints and other physical Fingerprints and other physical

impressionsimpressions Dusted to make visible, lift, storeDusted to make visible, lift, store

Forensic ScienceForensic Science

Evidence Gathering ToolsEvidence Gathering Tools Five sensesFive senses GlovesGloves Notebooks and penNotebooks and pen CameraCamera PlasterPlaster Dusting powderDusting powder Etc.Etc.

Forensic ScienceForensic Science

Forensic LaboratoryForensic Laboratory Sterile LabSterile Lab FiberFiber FingerprintFingerprint HairHair DNADNA Etc.Etc.

Forensic ScienceForensic Science

““Backpack Mystery”Backpack Mystery”