Investigative Photography

Physical evidence is any object that can establish that a crime has been committed or can link a crime and its victim or its perpetrator.

Forensic science begins at the crime scene. The investigator must recognize physical evidence & properly preserve it for laboratory examination.

The evidence must be kept in its original condition as much as possible.

Secure & Isolate the Crime Scene First priority is medical assistance to individuals &

arresting the perpetrator. Ropes or barricades and guards will prevent

unauthorized access to the area. Every person who enters the crime scene has the

potential to destroy physical evidence. The lead investigator evaluates the scene &

determines the boundaries. They do an initial walk through & develop a strategy.

All items must be documented & photographed.

3 methods of crime-scene recording: photography, sketches, & notes

Ideally all 3 should be used

SceneMultiple views

EntrancesExitsWindows

EvidenceEvidenceClose upsClose upsPerspectivesPerspectivesMultiple Multiple anglesangles

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The crime scene should be unaltered, unless injured people are involved, objects must not be moved until they have been photographed from all necessary angles. If things are removed, added, or positions

changed the photographs may not be admissible evidence.

Photograph completely Area where crime took place & adjacent areas Various angles

If crime scene includes a body: Take photos to show body’s location & position

relative to the whole crime scene Take close-up photos of injuries & weapons lying

near the body After the body is removed, photograph the

surface underneath. When size is significant, use a ruler or other

measuring scale Digital cameras allow for enhancement &

examination in fine detail. Videotaping a scene is also becoming

popular.

1. To record the original scene and related areas

2. To record the initial appearance of physical evidence

3. It will provide investigators and others with this permanent visual record of the scene for later use

4. Photographs are also used in court trials and hearings

1. Three major points of qualification of a photograph in court

a. Object pictured must be material or relevant to the point in issue

b. The photograph must not appeal to the emotions or tend to prejudice the court or jury

c. The photograph must be free from distortion and not misrepresent the scene or the object it purports to reproduce

2. You do not need to be an expert in photography to take crime scene photographs or testify about them

Any picture an officer takes may wind up in Court.

You will be safe if you keep this in mind for every photo you shoot.

Experience has shown that attention to a few simple rules can make pictures acceptable to most judges.

Purpose a. To show the scene exactly as it was

when you first saw it (1) If something was moved before you

arrived, don't try to reconstruct the scene as it was.

The photographs should show the scene as you found it

a. First discuss the crime, evidence and photographs needed with other investigators at the scene

b. Be careful not to destroy any evidence while taking the photographs

(1) Exterior of the building where the crime occurred and in some cases the whole locale

(2) Aerial photographs of the scene and the surrounding area can be useful in some types of cases

(3) Original series of photographs should also show all doors, windows and other means of entrance or exit

(1) Begin with a view of the entrance (2) Then photograph the scene as it

appears when you first step into the room (3) Next, move around the room to get

photographs of all the walls (a) These photographs should also show the

positions of any potential items of evidence (4) Include photographs of other rooms

connected with the actual crime scene

1. Take two photographs of each item of evidence a. One should be an orientation (midrange)

shot to show how the item is related to its surroundings

b. The second photograph should be a close-up to bring out the details of the object itself

2. Measuring and marking devices a. Take two photographs if a marking or

measuring device is used (1) One photograph without the device, the

other with the device (2) So the defense can't claim that the scene

was altered or that the device was concealing anything important

Each crime scene has unique characteristics and the type of photographs needed will be determined at the scene by the investigator familiar with the crime.

1. Use color film 2. Photographs (example: homicide inside

a residence) a. Exterior of the building b. Evidence outside the building c. Entrance into the scene d. Room in which the body was found

e. Adjoining rooms, hallways, stairwells

f. Body from five angles g. Close-up of body wounds h. Weapons i. Trace evidence

j. Signs of activity prior to the homicide

k. Evidence of a struggle l. View from positions witnesses had at time of the crime(1) Use a normal lens m. Autopsy

1. If there is any doubt, photograph the scene as a homicide

1. Photographing injuries a. Face of victim in the photographs b. Bruises c. Bite marks

(1) Orientation shot (2) Close-up at 90 degree angle to avoid distortion (3) Ruler in same plane as bite mark (4) Focus carefully (5) Bracket exposures

Fingerprints 1. When to photograph fingerprints a. Before lifting on major cases or if the latent may be destroyed when lifting

b. To bring out detail in a latent

1. Footprints and tire tracks a. Procedure

(1) Take an orientation photograph to show where in the scene the impression is located

(2) Take a close-up for detail (a) Use a scale on the same plane as the impression

1. Use color film 2. Orientation photographs to show

locations of bloodstain evidence at the scene

3. Close-up photographs to show detail a. Use a scale on the same plane as the

bloodstain b. Keep the film parallel to the plane of the

bloodstain

Does this picture reveal the true position of the witness to the crime?

Do the skid marks seem longer or shorter in the viewfinder than they are in real life?

How large is the lead pipe used as a weapon?

Shoot most pictures with the camera at eye level.

This is the height from which people normally see things and that makes it easier to judge perspective.

One practical way to assure complete coverage and to provide correct perspective is to follow the FOUR CORNER APPROACH. (Fig.1)

Once photos are taken, sketch the scene. A rough sketch is a sketch, drawn at the crime

scene, that contains an accurate depiction of the dimensions of the scene & shows the location of all objects having a bearing on the case. All measurements are made with a tape measure Show all items of physical evidence Assign each item a number or letter and list it in the

legend Show a compass heading designating north

A finished sketch is a precise rendering of the crime scene, usually drawn to scale. Computer-aided drafting (CAD) has become the

standard.

Rough-sketch diagram of a crime scene. Courtesy Sirchie Finger Print Laboratories, Inc., Youngsville, N.C., www.sirchie.com.

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Note taking must be a constant activity throughout the processing of the crime scene.

The notes may be the only source of information to refresh memory.

Tape-recording notes at a scene can be advantageous – detailed notes can be taped much faster than they can be written.

Once found, physical evidence must be collected & stored in a way that preserves its integrity for forensic comparison & analysis.

The search for physical evidence must be thorough and systematic, even when suspects are immediately seized.

A forensic scientist is not usually needed at the scene unless the evidence is complex or it is a major crime.

Some police agencies have trained field evidence technicians.

One person should supervise & coordinate. Include all probable entry & exit points in

search What to search for will be determined by

the particular circumstances of the crime. Examples

Homicide Hit-and-run

In most crimes, a search for latent fingerprints is required.

The crime scene coordinator may choose from a variety of crime scene search patterns based upon the type and size of the crime scene.

(a) Spiral

(b) Strip/Line

(c) Grid

(d) Zone/Quadrant

(e) Pie/Wheel

Physical evidence can be anything from massive objects to microscopic traces.

It may be necessary to take custody of all clothing worn by the participants in a crime. Handle carefully & wrap separately to avoid loss

of trace evidence. Critical areas of the crime scene should be

vacuumed & the sweepings submitted to the lab for analysis.

Mobile crime-scene vehicles carry supplies to protect the crime scene; photo, collect, & package evidence; & develop latent fingerprints.

The integrity of evidence is best maintained when the item is kept in its original condition as found at the crime scene.

The entire object should be sent to the lab. If evidence is found adhering to a large

structure, remove specimen with forceps or other appropriate tool. In the case of a bloodstain, one may either scrape

the stain off the surface, transfer the stain to a moistened swab, or cut out the area of the object containing the stain.

Each different item or similar items collected at different locations must be placed in separate containers.

Packaging evidence separately prevents damage through contact and prevents cross-contamination.

Medical examiner or coroner carefully examines the victim to establish a cause & manner of death.

Tissues are retained for pathological & toxicological examination.

The following are collected & sent to the lab: Victim’s clothing Fingernail scraping Head & pubic hairs Blood (DNA typing) Vaginal, anal, & oral swabs (in sex-related crimes) Recovered bullets from the body Hand swabs from shooting victims (for GSR analysis)

Forceps Unbreakable plastic pill bottles w/ pressure

lids Manila envelopes, glass vials, pill boxes Paper bags are better than plastic…why? Fire evidence must be kept in an airtight

container to prevent evaporation of petroleum residues

Clothing must be air-dried & placed in individual paper bags.

http://www.crime-scene.com/ecpi/evidence_collection.shtml

Chain of custody is a list of all people who came into possession of an item of evidence.

Chain must be established whenever evidence is presented in court as an exhibit. Failure to do so may lead to ? Regarding

authenticity & integrity of evidence. All items should be carefully packaged and

marked upon their retrieval at crime sites. Normally, the collector’s initials & date of

collection are inscribed directly on the article. The evidence container must also be marked

with collector’s initials, location of evidence, & date of collection.

The examination of evidence often requires comparison with a known standard/reference sample. A standard/reference sample is physical evidence

whose origin is known, such as blood or hair from a suspect, that can be compared to crime scene evidence.

Such materials may be obtained from the victim, a suspect, or other known sources.

The presence of standard/reference samples greatly facilitates the work of the forensic scientist.

Bloodstained evidence must be accompanied by a whole-blood or buccal swab s/r sample obtained from all relevant crime-scene participants. A buccal swab is a swab of the inner cheek, performed

to collect cells for use in determining the DNA profile of an individual.

Some types of evidence must also be accompanied by the collection of substrate controls. Normally collected at arson scenes. A substrate control is uncontaminated surface

material close to an area where physical evidence has been deposited; used to ensure that the surface on which a sample has been deposited does not interfere with laboratory tests.

Evidence is submitted to the lab either by personal delivery or by mail shipment.

Most labs require that an evidence submission form accompany all evidence submitted. Enables the lab analyst to make an intelligent &

complete examination of the evidence. Provide a brief description of the case history so

the examiner can analyze in a logical sequence. The particular kind of examination requested for

each type of evidence should be delineated. A list of all items submitted must be included.

Forensic Pathology involves the investigation of unnatural, unexplained, or violent deaths.Forensic pathologists in their role as

medical examiners or coroners are charged with determining cause of death.

The forensic pathologist may conduct an autopsy which is the medical dissection and examination of a body in order to determine the cause of death.

The increasing spread of AIDS and hepatitis B has sensitized the law enforcement community to the potential health hazards that can exist at crime scenes.

In reality, law enforcement officers have an extremely small chance of contracting AIDS or hepatitis at the crime scene.

The International Association for Identification Safety Committee has proposed guidelines to protect investigators at crime scenes containing potentially infectious materials that should be adhered to at all times.