Crime Scene Specialties

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Crime Lab — Basic Services

Physical Science Unit Chemistry Physics Geology

Biology Unit

Firearms Unit

Document Examination Unit

Photography Unit

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Most crime labs are backlogged and there has been a “triage” system developed to help analyze the sample from the most “serious” cases, murder & sexual assault

Physical Science Unit Crime Lab —Basic Services

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Applies principles of chemistry, physics and geology to identify and compare physical evidence such as:

• Drugs • Glass• Paint• Explosives• Soil

Biology UnitCrime Lab—Basic Services

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Applies knowledge of biological sciences to investigate samples such as:

• Blood• Body fluids (DNA) • Hair• Fibers• Botanical samples (ex. wood, plants)

Firearms UnitCrime Lab—Basic Services

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Examines:• Firearms• Discharged bullets• Cartridge cases• Shotgun shells• Ammunition of all types• Garments and other objects for firearms discharge residues• Approximate distance from target to weapon

Document Examination UnitCrime Lab—Basic Services

• Studies handwriting and typewriting on questioned documents to determine authenticity and/or source

• Analyze paper and ink

• Examine indented writings, obliterations, erasures and burned or charred documents

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Photography UnitCrime Lab—Basic Services

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Use of highly specialized photographic techniques to make invisible information visible to the naked eye, such as:

• Infrared• Ultraviolet• X-ray photography

Photographs crime scenes and physical evidencePrepares photographic exhibits for court

Photography Unit

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Optional Services Provided by Full-Service Crime Lab

• Fingerprint Unit & Latent Fingerprint processes and examines evidence for latent fingerprints.

• Polygraph Unit conducts polygraph or lie detector tests.

• Voiceprint Analysis Unit attempts to tie a recorded voice to a particular suspect.

• Evidence-Collection Unit dispatches specially trainedpersonnel to the crime scene to collect and preserve physical evidence.

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An envelope containing anthrax spores along with an anonymous letter was sent to the office of Senator Tom Daschle shortly after the terrorist attacks of September 11, 2001. A variety of forensic skills were used to examine the envelope and letter. Also, bar codes placed on the front and back of the envelope by mail-sorting machines contain address information and information about where the envelope was first processed. Courtesy Getty Images, Inc.—Liaison

Several Units coming together on 1 piece of evidence

Special Forensic Science Services Forensic Pathology

Forensic Entomology

Forensic Odontology

Forensic Anthropology

Forensic Toxicology

Forensic Psychiatry

Forensic Engineering

Forensic Computer and Digital Analysis

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Forensic Pathology

Concerned with determining the cause of death

Examines wounds and injuries

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A forensic pathologist examines a kidney during an autopsy.

“This is the place where the dead shall teach the living.”

Forensic Entomology

• Uses insects to help law enforcement determine the cause, location and time of death (TOD) of a human being

• Insect life cycles act as precise clocks which begin within minutes of death• Used to determine the TOD when other methods are useless

• Insects can also show if a body has been moved after death

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Forensic Odontology

• Helps identifies victims based on dental evidence

• Bite mark analysis - compare marks left of a victim and the tooth structure of a suspect

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Bite Marks

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Pattern injury displaying ovoidpattern and central bruising

Pattern injury displaying linearinterrupted abrasions

Forensic Anthropology

• Assist in identification of deceased individuals whose remains are decomposed, burned, mutilated or otherwise unrecognizable

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An anthropologist exhumes an unidentified set of remains from a Sarajevo cemetery. Forensic anthropology teams match these and thousands of other remains from conflicts around the world with DNA samples from family members of missing relatives. Photo by T.J. Grubisha 2002, U.S. State Department.

Forensic Toxicology

• The effects of poisons, toxins and drugs in the body. • Blood & breath alcohol determination

• Urine & hair testing for a “drug-free workplace”• “Date rape” drugs in a sexual assualt victim

• Not to be confused with “drug” analysis in the physical crime unit. Drug analysis is simply identifying the substance• For example: is this white powder in fact cocaine

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Forensic Psychiatry

• Examines relationship between human behavior and legal proceedings is examined• Determine if person is competent to stand trial

• Examines behavior patterns of criminals as an aid to developing a suspect’s behavioral profile

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Forensic EngineeringConcerned with

• failure analysis

• accident reconstruction

• causes and origins of fires or explosion

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Forensic Computer Science + Digital Analysis

• Identifying, collecting, preserving, and examining information derived from computers and other digital devices, such as cell phones• Recovering deleted or overwritten data from a computer’s

hard drive

• Tracking hacking activities within a compromised system

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Expert Witness

Everyone of these specialists could be an expert witness called to testify in court about the work they or someone

else conducted in the lab.

They are individuals who by knowledge, training or experience are qualified to discuss their experiences in

court

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Dr. Henry Lee

Dr. Lee was an expert witness for several high profile cases, he is also one of the authors of your textbook

http://www.youtube.com/watch?v=u26d8W5i2JU

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Dr. Jan Garavaglia (Dr. G)

Dr. G’s (expert medical examiner) testimony during the Casey Anthony Trial in the death of Caylee Anthony her two-year old daugher who was missing for 31 days prior to contacting the police.

http://www.youtube.com/watch?v=ybNUo2EM7b8

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