Science and ForensicsScience and Forensics

Garth GlassburgGarth Glassburg

NIRCLNIRCL

Within Within natural science, disciplines that are , disciplines that are basic science, also called pure science, , also called pure science, develop develop informationinformation to predict and perhaps to predict and perhaps explain—thus somehow understand—explain—thus somehow understand—phenomena in the natural world.phenomena in the natural world.

We are HereWe are Here

Applied scienceApplied science is a discipline that is a discipline that applies existing scientific knowledge to applies existing scientific knowledge to develop more practical applications, such develop more practical applications, such as technology or inventions. as technology or inventions.

Examples include medical applicationsExamples include medical applications

EngineeringEngineering

And of our interest-ForensicsAnd of our interest-Forensics

TermsTerms

We all use terminology, but is our We all use terminology, but is our understanding justified?understanding justified?ScienceScienceArtArtTheoryTheoryHypothesisHypothesisLawLawScientific MethodScientific Method

ErrorError

BiasBias

UncertaintyUncertainty

AccuracyAccuracy

Steps for Scientific MethodSteps for Scientific Method

Scientific researchers propose hypotheses Scientific researchers propose hypotheses as explanations of phenomena as explanations of phenomena

Experiments to test HypothesisExperiments to test Hypothesis

Must be repeatableMust be repeatable

Proposes a Theory Proposes a Theory

Proposes a LawProposes a Law

TheoryTheory

““JUST A THEORY- commonly phrased JUST A THEORY- commonly phrased and misusedand misused

A Theory is a very strong explanation of A Theory is a very strong explanation of results. Results are repeated and the results. Results are repeated and the Theory explains why these observations Theory explains why these observations have been occurhave been occur

A thread-fingerprints are uniqueA thread-fingerprints are unique

Nowhere does it say to have theory that Nowhere does it say to have theory that every item has to be testedevery item has to be tested

The sediment that fingerprints are not The sediment that fingerprints are not unique because every person not unique because every person not compared is a canardcompared is a canard

Same for Firearms ect.Same for Firearms ect.

Back to anything is possible? Or do we Back to anything is possible? Or do we mature?mature?

Scientific LawScientific Law

A law in A law in science is a generalized rule to explain is a generalized rule to explain a body of observations in the form of a verbal or a body of observations in the form of a verbal or mathematical statement. Scientific laws imply a mathematical statement. Scientific laws imply a cause and effect between the observed cause and effect between the observed elements and must always apply under the elements and must always apply under the same conditions.same conditions.

Scientific laws do not try to explain the 'why' the Scientific laws do not try to explain the 'why' the observed event happens, but only that the event observed event happens, but only that the event actually occurs the same way over and over.actually occurs the same way over and over.

On Being a ScientistOn Being a Scientist

IntegrityIntegrity

Data SharingData Sharing

Appreciation of how the future and present Appreciation of how the future and present will be/is built on the pastwill be/is built on the past

Reporting-(positive effect of accreditation)Reporting-(positive effect of accreditation)

Correct statistical reporting Correct statistical reporting

(National Academy of Sciences)(National Academy of Sciences)

FirearmsFirearms

An ExampleAn Example

McCluskey CaseMcCluskey Case

US District Court for the District of New US District Court for the District of New MexicoMexico

Three day hearingThree day hearing

DefenseDefense

No points of similarity on photographsNo points of similarity on photographs

Theory that firearms toolmarks are unique Theory that firearms toolmarks are unique and reproducible not provenand reproducible not proven

Used NAS reportUsed NAS report

Firearms is a Pseudo-science at bestFirearms is a Pseudo-science at best

No error rateNo error rate

Adina SchwarzAdina Schwarz

Associate Professor John JayAssociate Professor John Jay

Reviewed LiteratureReviewed Literature

Advocate for non-admission of ballisticsAdvocate for non-admission of ballistics

ARTART

The expression or application of human The expression or application of human creative skill and imagination, typically in a creative skill and imagination, typically in a visual form such as painting or sculpture visual form such as painting or sculpture

CreativeCreative

No peer review-anathema to a ArtNo peer review-anathema to a Art

Rules?Rules?

Conduct?Conduct?

No SOPNo SOP

Works produced by such skill and Works produced by such skill and imaginationimagination

Art has no object. An artwork is its own Art has no object. An artwork is its own object. object.

More on ArtMore on Art

Creative-so is scienceCreative-so is science

PossibilitiesPossibilities

Discovery-so is scienceDiscovery-so is science

Justification of thoughtJustification of thought

Searching vs. understanding the universeSearching vs. understanding the universe

Feelings vs FactsFeelings vs Facts

Major Differences with Art and Major Differences with Art and ScienceScience

Science is data drivenScience is data driven

RepeatabilityRepeatability

Rules in ScienceRules in Science

EthicsEthics

Peer ReviewPeer Review

ConsiderationsConsiderations

Jettison the idea of “comfort”Jettison the idea of “comfort”

Replace with confidenceReplace with confidence

Do you want to debate with your staff “I Do you want to debate with your staff “I am not comfortable with this report”am not comfortable with this report”

Or “I am not confident with the reports Or “I am not confident with the reports conclusions”, not complete, data does not conclusions”, not complete, data does not support this conclusion etc. Are you an support this conclusion etc. Are you an Artist or Scientist?Artist or Scientist?

Back to the Firearm CaseBack to the Firearm Case

The court rejected the position that an The court rejected the position that an identification was in exclusion of all other identification was in exclusion of all other firearmsfirearms

However it did say that a “practical However it did say that a “practical certainty”, not an absolute certainty is certainty”, not an absolute certainty is acceptableacceptable

This was the acceptable standardThis was the acceptable standard

One way to look at this is that since people One way to look at this is that since people are fallible, an absolute ID is not possible, are fallible, an absolute ID is not possible, but the practical certainty is acceptable. but the practical certainty is acceptable.

Defense RejectedDefense Rejected

Defense analysis is biased Defense analysis is biased

Not peers in the fieldNot peers in the field

Error rate was determined not to existError rate was determined not to exist

Was not needed to determine if Firearms Was not needed to determine if Firearms is a science and can be admitted.is a science and can be admitted.

PrintsPrints

Long historyLong history

AFIS hitsAFIS hits

Never had two people with the same printNever had two people with the same print

Theory partially based on embryologyTheory partially based on embryology

Do you really think that this has not been Do you really think that this has not been peer reviewed, that if embryologists peer reviewed, that if embryologists questioned the basis of ridge detail it questioned the basis of ridge detail it would not be published?would not be published?

The science for Prints is well establishedThe science for Prints is well established

Data is evaluated, 1Data is evaluated, 1stst, 2, 2ndnd, 3, 3rdrd level detail level detail

This alone precludes this from being an This alone precludes this from being an ArtArt

Personal NotesPersonal Notes

Such defenses never offer dataSuch defenses never offer data

Just critic the work Just critic the work

Without data there is no hypothesisWithout data there is no hypothesis

No theoryNo theory

No LawNo Law

But they talk a good game and must be But they talk a good game and must be confronted confronted

SWGDRUGSWGDRUG

Qualitative Analysis Qualitative Analysis The identification of seized drugs requires the combination of The identification of seized drugs requires the combination of methods to form an analytical scheme (see PART III B - Methods of methods to form an analytical scheme (see PART III B - Methods of Analysis/Drug Identification). Analysis/Drug Identification). 2.1 2.1 Individual methods have limitations and, consequently, Individual methods have limitations and, consequently, uncertainty. Uncertainty of qualitative methods is not typically uncertainty. Uncertainty of qualitative methods is not typically expressed in numerical terms. expressed in numerical terms. 2.2 2.2 Understanding these limitations enables the laboratory or Understanding these limitations enables the laboratory or analyst to build an appropriate analytical scheme to correctly identify analyst to build an appropriate analytical scheme to correctly identify a drug or chemical. a drug or chemical. 2.2.1 It is expected that, in the absence of unforeseen 2.2.1 It is expected that, in the absence of unforeseen circumstances, an appropriate analytical scheme effectively circumstances, an appropriate analytical scheme effectively results in no uncertainty in reported identifications.results in no uncertainty in reported identifications.

Bottom LineBottom Line

Forensic Applications as we use them are Forensic Applications as we use them are a sciencea science

Not an ArtNot an Art

Give ourselves more creditGive ourselves more credit

But be able to explain WHY we are But be able to explain WHY we are scientistsscientists

More Bottom LineMore Bottom Line

I feel that the individual Forensic Scientist I feel that the individual Forensic Scientist should reacquaint herself with the concept should reacquaint herself with the concept of science and the scientific methodof science and the scientific method

Will future Forensic bodies support this? Will future Forensic bodies support this? Time will tell.Time will tell.