The study and application of science to matters of law

The study and application of science to matters of law

• The study and application of science to matters of law

• Includes the business of providing timely, accurate, and thorough information to all levels of decision makers in our criminal justice system

• The word forensic is derived from the Latin forensis meaning forum, a public place where, in Roman times, senators and others debated, performed, and held judicial proceedings.

Criminalistics

• Criminalistics

• The scientific examination of physical evidence for legal purposes

• Criminology

• Includes the psychological angle: studying the crime scene for motive, traits, and behavior that will help to interpret the evidence

Physical science unit

• Physical science unit

• Chemistry
• Physics
• Geology

• Biology unit

• Firearms and ballistics unit

• Document examination unit

• Photography unit

• The most common types of evidence examined are drugs, firearms, and fingerprints.

Crime labs can be government-run at the federal, state, or local level, or they can be private consulting businesses.

• Crime labs can be government-run at the federal, state, or local level, or they can be private consulting businesses.

• Toxicology unit

• Latent fingerprint unit

• Polygraph unit

• Voiceprint analysis unit

• Evidence collection unit

• Engineering

Forensic pathology

• Forensic pathology

• Forensic anthropology

• Forensic entomology

• Forensic psychiatry

• Forensic odontology

• Forensic engineering

• Cybertechnology

FBI: Federal Bureau of Investigation

• FBI: Federal Bureau of Investigation

• DEA: Drug Enforcement Agency

• ATF: Alcohol, Tobacco, and Firearms

• USPS: United States Postal Service

• U.S. Fish and Wildlife Service

• Department of Homeland Security

• Department of the Treasury

700 AD: Chinese used fingerprints to establish identity of documents and clay sculptures.

• 700 AD: Chinese used fingerprints to establish identity of documents and clay sculptures.
• 1000 (?): Roman courts determined that bloody palm prints were used to frame a man in his brother’s murder.
• 1149: King Richard of England introduced the idea of the coroner to investigate questionable deaths.
• 1248: A murder in China was solved when flies were attracted to invisible blood residue on the sword of a man in the community.
• 1514: Earliest known use of blood spatter evidence.
• 1598: Fidelus was first to practice forensic medicine in Italy.

1670: Anton Van Leeuwenhoek constructed the first high-powered microscope.

• 1670: Anton Van Leeuwenhoek constructed the first high-powered microscope.
• 1776: Paul Revere identified the body of General Joseph Warren based on the false teeth he had made for him.
• 1784: John Toms was convicted of murder on the basis of the torn edge of a wad of paper in a pistol matching a piece of paper in his pocket.
• 1859: Gustav Kirchhoff and Robert Bunsen
• developed the science of spectroscopy.

1864: Crime scene photography developed.

• 1864: Crime scene photography developed.
• 1879: Alphonse Bertillon developed a system to identify people using particular body measurements.
• 1896: Edward Henry developed the first classification system for fingerprint identification.
• 1900: Karl Landsteiner identified human blood groups.
• 1904: Edmond Locard formulated his famous principle, “Every contact leaves a trace.”

1922: Francis Aston developed the mass spectrometer.

• 1922: Francis Aston developed the mass spectrometer.
• 1959: James Watson and Francis Crick
• discovered the DNA double helix.
• 1977: AFIS developed by the FBI; fully
• automated in 1996.
• 1984: Jeffreys developed and used the
• first DNA tests to be applied to a criminal
• case.

Edmond Locard (1877–1966)

• Edmond Locard (1877–1966)

• French professor

• Considered the father of criminalistics

• Built the world’s first forensic laboratory in France in 1910

• Locard Exchange Principle:

• Whenever two objects come into contact with each other, there is always a transfer of material. 

At your desk

• At your desk

• What are you in contact with?
• What could transfer to you?
• What will you leave behind?
• How can you prevent transfers?
• What could be traced to you?
• Other than eyewitnesses what evidence is here at school that you were here today?
• Is it possible not to leave evidence?
• Could covering your tracks leave evidence as well?

A group of professional investigators, each trained in a variety of special disciplines

• A group of professional investigators, each trained in a variety of special disciplines

• Team members:

• First police officer on the scene
• Medics (if necessary)
• Investigators
• Medical examiner or representative (if necessary)
• Photographer and/or field evidence technician
• Lab experts:
• pathologist serologist
• DNA expert toxicologist
• forensic odontologist forensic anthropologist
• forensic psychologist forensic entomologist
• firearm examiner bomb and arson experts
• document and handwriting experts fingerprint expert

Observe a problem or questioned evidence and collect objective data.

• Observe a problem or questioned evidence and collect objective data.

• Consider a hypothesis or possible solution.

• Examine, test, and then analyze the evidence.

• Determine the significance of the evidence.

• Formulate a theory based on evaluation of the significance of the evidence.

In order for scientific evidence to be admitted in a court of law, it must be:

• In order for scientific evidence to be admitted in a court of law, it must be:

• Probative: actually proves something

• Material: addresses an issue that is relevant to the particular crime

There are five main stakeholders in the courtroom:

• There are five main stakeholders in the courtroom:

• Prosecutor

• Defense (representing the defendant)

• Forensic Scientist

• Judge

• Police officer/Detective

Gives legal advise in investigations

• Gives legal advise in investigations

• Sometimes writes or assists writing warrants, etc.

• Reviews case for potential trial issues

• - Plea bargaining option

• Discovery – provides Brady material

• Prepares case

• Defends evidentiary challenges – based on case law

• Subpoenas witnesses

• Introduce evidence

• Question witnesses – also establishes expert witnesses

Monitor’s defendants rights in pre-trial process

• Monitor’s defendants rights in pre-trial process

• Reviews case for potential trial issues

• May negotiate plea bargain

• Prepares case

• Makes evidentiary challenges – based on case law

• Subpoenas witnesses – if any, mostly alibi

• Introduce evidence – if any

• Question witnesses – Cross of prosecution case, may introduce counter testimony with own expert witnesses

May collect evidence

• May collect evidence

• Creates/maintains chain of evidence

• Processes evidence

• Interprets evidence

• Prepares reports

• Follows Constitutional requirements

• Often communicates with investigator about case

• Often communicates with prosecutor before trial

• May help prepare posters/materials for court

• Testifies to jury about evidence

Researches case law

• Researches case law

• Reviews motions

• Make decisions on evidentiary challenges

• Makes decisions on expert witnesses

• Makes decisions on details of case such as crime scene photos being used (shock effect on jury)

• Monitors trial

Manages crime scene

• Manages crime scene

• Oversees evidence collection – often done by officer

• Follows up on leads, questions witnesses

• Makes arrests

• Writes warrants

• Maintains extensive reports and notes

• May assist prosecutor with case preparation

• Prepares for court

The Frye Standard

• The Frye Standard

• From the 1923 case Frye v. United States

• Scientific evidence is allowed into the courtroom if it is generally accepted by the relevant scientific community. The Frye standard does not offer any guidance on reliability. The evidence is presented in the trial and the jury decides if it can be used.

• “the principle…must be sufficiently established to have gained general acceptance in the particular field in which it belongs.”

The Daubert Ruling

• The Daubert Ruling

• From the 1993 case Daubert v. Dow

• The judge decides if the evidence can be entered into the trial. Admissibility is determined by:

• Whether the theory or technique can be tested

• Whether the science has been offered for peer review

• Whether the rate of error is acceptable

• Whether the method at issue enjoys widespread acceptance

• Whether the theory or technique follows standards

The expert witness presents scientific evidence in court. He/She will:

• The expert witness presents scientific evidence in court. He/She will:

• Establish credibility by citing:

• educational degrees
• participation in special courses
• membership in professional societies
• published articles and books
• years of experience

• Evaluate evidence: Subject to cross-examination

• Render an opinion about the evidence. The judge may accept or reject the opinion’s significance.

• Only courtroom actor allowed to express an opinion

To prove a case, the “MMO” must be established; it must be shown that the suspect had:

• To prove a case, the “MMO” must be established; it must be shown that the suspect had:

• Motive—person had a reason to do the crime (not necessary to prove in a court of law)
• Means—person had the ability to do the crime
• Opportunity—person can be placed at the crime scene

TV shows and Hollywood often portray forensics in a sensational way. Major issues:

• TV shows and Hollywood often portray forensics in a sensational way. Major issues:

• - Not all crimes have copious amounts of evidence

• - Rarely do scientist/techs do investigations

• - Labs are far from fancy

• - Most testimony is scientific detail

• - Staff are not glamorous

• - Lab results may take months

A man took a slug of what he thought was whiskey. It wasn’t; it was concentrated sulfuric acid!

• A man took a slug of what he thought was whiskey. It wasn’t; it was concentrated sulfuric acid!

• Was a crime committed?