Lecture 1: Introduction to Forensics

Lecture 1

What is forensic science?

• Good forensics shows: 48 hrs, forensic files, new detectives & unusual suspects

• CSI effect makes people think that forensics is an all-encompassing thing that is simple and solves all types of cases, or that you will always have dna

• Defined as use of science and technology to enforce civil and criminal laws, applying a broad range of sciences and tech to establish fact of interests

Applying Science to Law

• Depends on a scientist’s ability to supply accurate info- your job is to display evidence properly without bias to anyone involved

• Forensics is always always evolving

New technology

• Alexa is always listening and may have heard evidence or the name of a suspect

• Amazon has been brought to court because of this before

• Fitness watches can provide a time of death since they're tracking your heart rate

People to know

• Mathieu Orfuila- founder of toxicology

• Sir Conan Doyle- sherlock!

• Francis Galton- father of fingerprinting

• Alphonse Bertillon- developed body measurement system

• Victor Balthazard- advanced fingerprinting & firearm analysis & hair analysis

• Leone Lattes- father of bloodstain ID

• Calvin Goddard- father of ballistics; instrumental in St. Valentine’s day massacre case

• Albert Osborn- father of document examination

• Edmond Locard- father of crime lab!!! Created “Locard’s Exchange Principle”

  • Every contact leaves a trace, so evidence is always transferred

• J. Edgar Hoover- father of FBI, controversial as he abused his power with illegal wiretaps and unjustified investigations

  • He is why fbi heads cannot be 10+ years

• Walter McCrone- father of microscopic forensics

Elucidation of Forensic DNA

• Watson & crick stole research from rosalind franklin and never credited her

Forensic Lubricants

• Used evidence from rape/ sodomy cases where lubricants were used in order to substitute as evidence for DNA

Criminal Justice System

• Responding officer (secure scene) -> crime scene -> detective (interview suspects and witnesses) -> forensic scientists (duh) -> lawyers/ courtroom (fight the case) -> jury

Types of crime labs

• Federal (homeland, secret service, post office, ATF, DEA) , military (cyber crimes, army criminal investigation) , state (FDLE, state of FL BI), county, local, private (walmart, target, quest)

  • County & local will usually send complex evidence to higher up labs like FDLE

National Commission on Forensic Science

• Made standard operating procedures crime labs to use in regards to ethics

Accreditation & Certification

• Issued to lab, demonstrate all services meet standard (don't have to be accredited to do analysis)

• Certification is a written exam and requires a yearly proficiency test, multiple disciplinary exams

Categories of Evidence

• Inculpatory (include person as a suspect) or exculpatory (exclude person as a suspect)

• Direct (need no add’l info) or circumstantial (not entirely factual, needs add’l info

• Reconstructive (what detectives do)

• Associative (point towards a suspect, i.e. blood type)

• Class (refers to a group of ppl) or individual (refers to a specific person)

  • Class- common to a group, increase probable value of narrowing down

  • Individual- unique features like fingerprints, handwriting, specific chip in your specific footprint

• Practice: torn shirt is found in suspect’s car. It’s similar to two pieces of similar cloth found at a crime scene.

  • Individual or class? 

    • class

  • What other types of evidence could be found on the shirt?

    • Sweat, makeup, hair, spit, blood

Types of Evidence

• Bio- human tissue

• Chemical- drugs or explosives

• Trace- microscopic physical evidence

  • Ex. fire debris, explosives, paint, fibers, hair, soil

• Fingerprint

• Documents- handwriting or alterations

• Impressions- tires, shoes and tool marks

Crime Scene Investigation

• Looking for blood spatter, fingerprints, body positioning, footprints or fingerprints

Chain of Command

• Technician -> technologist -> scientist/ analyst -> technical leaders -> supervisor/ branch chief -> lab quality manager

Chain of Custody

• This one shows up in court and indicates if evidence has been changed or altered

• CSI tech -> post office/ hand delivery -> scientists/ analyst #1 -> scientists/ analyst #2 -> post office/ hand delivery -> attorney/ court

• Each person whose hands it passes through must place a seal indicating they had it and when, the next person can NOT take off the one before’s seal

Goals of forensics

• Support justice system

• Seek truth of evidence

• Draft a perfect report

• Advance the field

• Educate audiences

Daily activities

• Evidence processing (analyze & interpret)

• Testifying in court

  • Remember you don’t know how long it’ll be between analyzation & court, so take DETAILED notes on your analysis of the evidence and why you think what

• Speak with investigators

• Not go to crime scenes or speak to witnesses

• OUR JOB IS TO SPEAK FOR THE EVIDENCE

The Body Farm

• To understand processes of post mortem decay, they simulate various crime scenes using REAL HUMAN BODIES

• You’re supposed to donate your body to a body farm when you die to then be studied, or they also use unclaimed bodies

• Started in 70s 

• Used by law enforcement, medical examiners, FBI for training, entomologists & cadaver dogs

• Only 7 facilities in the US but they’re all around the country in different biomes & environments

Law & Expert Testimony

• Forensic scientists provide expert testimony for many crime cases to enforce the law

Lawyers vs. Forensic Scientists

• Forensic scientists function purely off data and analyze it with scientific method, not flexible

• Lawyers see shades of gray, use evidence to support their argument or try to go against it

Legal Proceedings: Rules

• Trier- finder of fact

• Prosecution bears burden of proving defendant guilty beyond a reasonable doubt

• Plaintiff proves the case by preponderance of evidence

• Defendant is the victim

• Forensic scientist can testify on whichever side calls you, sometimes both- whichever your evidence supports more

Forensic’s Day in Court

• Analysis -> report -> subpoena

• Court will perform voir dire on you (what are your qualifications, are you qualified to be here?)

• Direct examination lays the foundation for the admissibility of evidence

• Cross-examination tries to discredit you

Law & Expert Testimony

• Expert witness is someone with extensive training and qualification in a specific discipline, while a fact or lay witness is someone untrained but they just happen to be a witness for the case (like an eyewitness)

  • Eyewitness can only testify to what you SAW, not use past knowledge

• Scientists must speak unbiased, professionally, in a neutral tone, unwavering and in layman’s terms in a court

• Witness must be aware of admissibility criteria of evidence you’re testifying on (reason for frye & daubert hearing)

Forensic Scientist lingo

• Learn to speak 2 different ways: to other colleagues, and to jurors/ attorneys

Rules of Evidence

• All exclusionary- relating on how you get evidence out of court and not admissibile

• Forensics uses scientific, court uses litigation

The Frye Test

• Way to test admissibility of evidence

• James Frye was charged with murder and psychologust wanted to use a blood pressure monitor to see if he was lying during testimony

• Created “general acceptance” test to admit evidence- proponent must show that theory is generally accepyted within community in order to admit

The Daubert Test

• Daubert and brother were both born with birth defects, parents sued pharmaceutical company

• Parents submitted scientific articles showing link between medicine and defects, but bc it wasn’t generally accepted it was rejected and company won

• Led to official Gatekeeper Rule & overrode Frye test at federal level, prioritizing peer review of data, acceptance of community, validated methods and all to show the evidence is validated and can be admitted

Federal Rule 702: Admissibility of Expert Witness

• If knowledge will assist the trier of fact to understand evidence in issue, a qualified witness may testify in the form of an opinion if:

  • Testimony is fact based

  • The product of reliable data

  • Has applied the principles and methods reliably

Florida’s Admissibility of Scientific Evidence

• 1952: frye standard state

• 2013: passed Bill 7015 to overrule frye standard

• 2017: declined to adopt “Daubert Amendment”, essentially reverted to Frye Standard again

Kumho Tire Rule

• Gatekeeping applied to not only scientific testimony but to all expert testimony, usually requires a voir dire

  • I.e. you can be excepted as an expert witness if you know your profession, don't have to be strictly scientific

The Daubert Trilogy

• Daubert vs. Merrell Dow (gatekeeper)

• G.E. vs. Joiner (relevance)

• Kumho tire vs. Carmichael (all experts)

Admissibility

• Evidence must be properly collected

• Specific to home territory