Forensic Science and Crime Scene Investigation Review

Comprehensive practice flashcards covering Forensic Science principles, historical pioneers, lab organization, physical evidence, and crime scene protocol.

How is Forensic Science defined in the context of criminal investigation?

Forensic Science is the application of science to criminal and civil laws, mainly on the criminal side during criminal investigation, as governed by the legal standards of admissible evidence and criminal procedure.

Under the Forensic Science class punctuality policy, what happens two minutes after the bell rings?

The classroom door will be locked, and any student arriving after that time is marked tardy and must report to Ms. Kimberly to obtain a late pass.

What contributions did Sir Arthur Conan Doyle make to the field of crime detection?

He popularized physical detection methods at crime scenes through his written works and created the legendary character Sherlock Holmes.

Why is Mathieu Orfila recognized as the Father of Forensic Toxicology?

In 1814, he published the first scientific treatise on the detection of poisons and their toxic effects on animals.

What personal identification system was created by Alphonse Bertillon in 1879?

Anthropometry, which was the first scientific system of personal identification based on precise body measurements.

What key work on fingerprinting was published by Francis Galton in 1892?

He conducted the first definitive study of fingerprints and their classification, publishing his findings in a treatise titled Finger Prints.

What method did Dr. Leone Lattes develop for analyzing dried blood evidence?

He devised a simple procedure for determining the blood group (A, B, AB, or O) of a dried bloodstain.

How did Calvin Goddard advance firearm identification in forensic science?

He utilized a comparison microscope to determine if a bullet was fired from a specific gun and published groundbreaking studies on tool marks on bullets.

What was Albert S. Osborn's primary contribution to question document analysis?

He developed the fundamental principles of document examination, authored the 1910 treatise Questioned Documents, and gained acceptance for documents as scientific evidence in court.

What is the core principle behind Locard's Exchange Principle?

It states that whenever contact occurs between two surfaces or objects, a transfer of materials will take place ('Every contact leaves a trace').

When and where was the oldest American forensics laboratory founded, and by whom?

It was established in 1923 in Los Angeles, California, by August Volmer.

When was the US national forensic laboratory established by J. Edgar Hoover?

In 1932, to support law enforcement agencies across the United States.

Which basic unit of a full-service crime lab analyzes evidence using chemistry, physics, and geology?

The Physical Science Unit.

What types of evidence are processed within a crime laboratory's Biology Unit?

Dried bloodstains, body fluids, hair, fibers, botanical materials such as wood and plants, and DNA samples.

Why is the Polygraph Unit classified as an optional service rather than a core forensic science unit?

Lie detectors function primarily as an investigative tool for law enforcement officers rather than as admissible scientific evidence evaluated by forensic scientists.

What characterizes the post-mortem stage known as Rigor Mortis?

It is the stiffening and shortening of body muscles that occurs immediately following death after initial muscle relaxation.

What causes Livor Mortis and what physical appearance does it create on a corpse?

It is caused by gravity pulling stagnant blood down to the lowest parts of the body after the heart stops, turning the skin dark blue or purple in those areas.

How is Algor Mortis defined and utilized by medical examiners?

It is the continual cooling of body temperature post-mortem until reaching ambient room temperature, which helps determine the estimated time of death.

What are the five official categories for manner of death?

Natural death, homicide, suicide, accident, and undetermined.

What role does forensic psychiatry serve in criminal proceedings?

It examines human behavior and mental competency, and evaluates psychological disorders to build suspect behavioral profiles.

How does forensic odontology assist in identifying victims or suspects?

By matching bite mark evidence to a suspect's unique dental characteristics or matching unknown human remains to historical dental X-rays.

What is the difference between a primary crime scene and a secondary crime scene?

A primary crime scene is the original location where the crime or accident occurred, whereas a secondary crime scene is an alternate location where additional evidence is recovered.

How do the definitions of an alibi and an accomplice differ?

An alibi is a statement establishing where a suspect was at the time of a crime, while an accomplice is a person associated with someone suspected of committing the crime.

What are the four primary steps in standard crime scene protocol?

1) Interview, 2) Examine, 3) Document, and 4) Process.

What are the primary duties of police officers who arrive first at a crime scene?

To secure the crime scene to prevent evidence destruction and detain suspects or persons of interest.

Why is a District Attorney present at a crime scene?

To assess whether search warrants are needed to proceed with evidence collection and to obtain those warrants from a judge.

How do direct evidence and circumstantial evidence differ?

Direct evidence includes firsthand observations such as eyewitness accounts or video recordings, while circumstantial evidence is indirect evidence that implies a fact without directly proving it.

Based on the evidence classification tree diagram, how is circumstantial evidence further subdivided?

Circumstantial evidence is divided into physical evidence and biological evidence.

From what type of criminal cases does the majority of paint evidence originate?

Hit-and-run automobile investigations.

How can paint evidence show individual characteristics rather than class characteristics?

When unique similarities exist between samples, such as matching color, layer sequence, chemical composition, or a physical fracture match between chip edges.

What information can be derived from analyzing windshield glass fracture patterns?

It reveals details regarding vehicle speed, occupant positioning, and the angle of impact.

What is the function of the IBIS database in forensic ballistics?

The Integrated Ballistics Identification System allows investigators to compare microscopic striations and markings from bullets, cartridge cases, and shotgun shells.

In firearm analysis, what do the terms 'caliber' and 'gauge' measure?

They specify the internal diameter size of a firearm's barrel.

What database is used across local, state, and national levels to search for fingerprint matches?

AFIS (Automated Fingerprint Identification System).

How can shoeprint impressions match a specific suspect to a crime scene?

By identifying brand tread patterns combined with individual wear patterns from the owner's walking style, as well as specific nicks, cuts, and scratches.

What defines a fracture match in physical evidence analysis?

The direct physical fit between two unique broken or torn edges formed when an object such as glass, tape, paint, or paper is fractured.

What FBI-maintained database contains DNA profiles for matching unknown crime scene samples?

CODIS (Combined DNA Index System).

Which specific bones are examined by forensic anthropologists to determine sex and stature?

Biological sex is determined primarily from the pelvis, humerus, and femur; stature is estimated using long bone growth and femur length.

What features of human skulls are evaluated during forensic anthropological analysis?

Ancestral morphological characteristics including jawline shape, European mandible structure, and cranial features.

What specific tasks fall outside the scope of a forensic anthropologist's duties?

Forensic anthropologists do not collect trace evidence, run DNA tests, analyze ballistics, analyze blood spatter patterns, or perform autopsies.

What are the Seven S's of Crime Scene Investigation in sequential order?

1) Securing the scene, 2) Separating the witnesses, 3) Scanning the scene, 4) Seeing the scene, 5) Sketching the scene, 6) Searching for evidence, and 7) Securing and collecting evidence.

Why is separating witnesses essential during a crime scene investigation?

To prevent witnesses from discussing the event and colluding or altering their memories.

What packaging procedure for trace evidence is demonstrated in this diagram?

Folding a paper bindle, placing evidence at the designated location, tucking the flaps, placing the bindle inside a labeled evidence bag, sealing it with tape, and signing across the taped edge.

What is the chain of custody and why must it be strictly maintained?

It is the unbroken chronological record tracking every person who collects, transfers, and analyzes evidence; maintaining it guarantees legal admissibility in court.

What mandatory details must be written on a crime scene evidence log?

Case number, item inventory number, evidence description, suspect name, victim name, date and time of recovery, signature of the collector, and witness signatures.

What is the goal of crime scene reconstruction?

To form a testable hypothesis of the sequence of events leading up to, during, and following the commission of a crime by analyzing evidence alongside witness statements.