Chapter 2: The Crime Scene

The first responding police office

Upon arrival at a crime scene, who is responsible for securing the scene?

Acquiring medical assistance for injured victims

What is the first thing the first responding police office must do?

Disturbing evidence and approach the victim by an indirect route

What should medical personnel avoid when providing assistance to injured victims?

Acquiring medical assistance for injured victims

Detaining any potential suspects or witnesses; secure appropriate statements.

Securing the crime scene to the greatest extent possible

Calling for any additional personnel needed, such as other officers and/or forensic investigators

Photography, sketches, and notes

What are the responsibilities of the first responding officer?

Photography, sketches, and notes

What are the three methods for crime-scene recording?

The lead investigator

Who will determine the boundaries of the scene and establish the perpetrator’s possible path of entry and exit?

Crime scene tape, ropes, or cones

What must the boundaries of the crime scene be secured with?

The area where the crime took place and the surrounding area where physical evidence may be located

What should the secured area include?

The guards may be posted to restrict access to the crime scene

What will happen when the boundaries are secured?

A detailed log

What is kept of personnel movements in and out of the crime scene?

It includes personnel names and time of entry or exit

What does the detailed log of personnel movements include?

They should never do anything that might alter the crime scene, including smoking, eating, drinking, or littering

What should investigators never do?

The identity of person who contacted the investigator

Time of contact and arrival at the crime scene

Preliminary case information

Personnel present on arrival and those being contacted

What should the crime scene notes include?

Notes contain a personnel log, all observations made by the investigator, and the time observations were made

What do crime scene notes contain?

In a uniform layout, concurrently as the observations are made

How are crime scene notes taken?

In a bound notebook in blue or black ink

Where are crime scene notes written?

Overview photograph

Medium-range photograph

Close-up photograph

Close-up photograph with a measurement scale, such as a ruler

What are the four minimum photographs required at a crime scene?

The proper progression of photographing the scene

What does the sequence of crime scene photographs show?

The Close-up Photographs

Taken last and show greater detail of individual objects or evidence

Taken at a 90° angle to the object, with and without evidence markers and scales

Scales should be placed as close to the evidence as possible without affecting it in any way

The Crime Scene Video

Must include overview, medium-range, and close up images

May be a body worn camera

What kind of camera may be used for crime scene video?

A narrated crime scene video

What kind of recording combines photography and notes?

It is important that only one person narrates and no side conversations are captured on the video

What is important when recording a narrated crime scene video?

Show measurements over long distances and topography of outdoor scenes

Depict possible paths of entry, exit, and movement through the scene

Clarify objects and features already described in notes or shown in photographs

What must you do when sketching the crime scene?

Strip or Line Search Pattern

Wheel or Ray Search Pattern

Grid Search Pattern

Spiral Search Pattern

examination at the crime laboratory

Many items of evidence are clearly visible but others may be detected only through…

clothing, vacuum sweepings, and fingernail scrapings, in addition to more discernible items

It is important to collect possible carriers of trace evidence, such as…

contamination, breakage, evaporation, accidental scratching or bending, or through improper or careless packaging

Investigators handle and process physical evidence in a way that prevents changes to the evidence through…

Latex gloves, disposable forceps, and sanitized equipment

What is used to reduce the chance for contamination?

in its original condition as found at the crime scene

One should keep evidence…

Manila evidence envelope

Metal pillboxes

Sealable plastic evidence bag

Disposable forceps and similar tools

What may have to be used to pick up small items?

Unbreakable plastic pill bottles with pressure lids

What are excellent containers for hairs, glass, fibers, and various other kinds of small or trace evidence?

Manila envelopes, screw-cap glass vials, or cardboard pillboxes

What are adequate containers for most trace evidence encountered at crime sites?

Ordinary mailing envelopes

What should not be used as evidence containers because powders and fine particles will leak out of their corners?

Sealable plastic evidence bags

What are ideal for drug evidence?

Druggist fold

Small amounts of trace evidence can also be conveniently packaged in a carefully folded paper, using what is known as a…

Airtight metal or glass containers to prevent the loss of accelerant vapors

What should evidence from arson scenes should be packaged in?

The accumulation of moisture may encourage the growth of bacteria and mold, which can destroy the evidential value

What will happen if biological or bloodstained materials are stored in airtight containers?

Air-dry before being packaged in butcher paper, manila envelopes, or paper bags

For packaging biological evidence, the material should be allowed to…

Standard/Reference Sample

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

Comparison with a known standard/reference sample

What does the examination of evidence, whether it is soil, blood, glass, hair, fibers, and so on, often require?

The chain of custody

What is a list of all persons who came into possession of an item of evidence, as well as when and where they were in possession of it?

Presented in court as an exhibit

Continuity of possession, or the chain of custody, must be established whenever evidence is…

Adherence to standard procedures in recording the location of evidence, marking it for identification, and properly completing evidence submission forms for laboratory analysis

What is critical to chain of custody?

Fourth Amendment privileges

The removal of any evidence from a person or from the scene of a crime must be done in conformity with…

The existence of emergency circumstances

The need to prevent the immediate loss or destruction of evidence

A search of a person and property within the immediate control of the person provided it is made incident to a lawful arrest

A search made by consent of the parties involved

The United States Supreme Court has determined that search and seizure without a court-approved warrant is justified in four cases…

Physical evidence

What encompasses all objects that can establish or disprove whether a crime has been committed or can link a crime and its victim or its perpetrator?

False

Scientific evaluation of crime-scene evidence can usually overcome the results of a poorly conducted criminal investigation

False

The techniques of physical evidence collection require a highly skilled individual who must specialize in this area of investigation

Excluded from crime scenes

All unauthorized personnel must be…

True

Failure to protect a crime scene properly may result in the destruction or altering of evidence

First officer

When arriving on the scene of a crime, who is responsible for taking steps to preserve and protect the area to the greatest extent possible, and this person must rely on his or her training to deal with any violent or hazardous circumstances?

Obtaining medical aid for individuals in need of it and attempting to minimize disturbance of evidence

At a crime scene, first priority should be given to…

False

The boundaries of the crime scene, denoted by crime-scene tape, rope, or traffic cones, should encompass only the center of the scene where the crime occurred

An accurate record or log of those who enter and exit the scene and the time they do so

Even though no unauthorized personnel are admitted to the scene, what must be kept of those who enter and exit the scene?

False

The lead investigator will immediately proceed to gain an overview of the situation and develop a strategy for the systematic examination of the crime scene during the final survey

Photography, sketching, and note-taking

What are the three methods for recording the crime scene?

True

Note-taking begins with the call to a crime-scene investigator to report to a scene

The first officer

The crime-scene notes should include a precise record of personnel movements in and out of the scene starting with…

False

Crime-scene notes should be written from memory back at the laboratory

Notes

Before located evidence is collected, it must be fully described in the investigator’s…

False

When an injured or deceased victim is present at the scene, the state of the body before being moved should be observed but not recorded

Unaltered condition

The most important prerequisite for photographing a crime scene is to have it in an…

Close ups to record the details of objects

Photographs of physical evidence must include overviews as well as…

False

The value of crime-scene photographs lies in their ability to show the layout of the scene, position of witnesses, and relation of people to one another in the scene

Single-lens reflex

What is the most commonly used camera for crime-scene photography?

Electric sensor

A digital camera captures light on a light sensitive…

True

Each crime scene should be photographed as completely as possible in a logical succession, and the photographs should include the area in which the crime actually took place and all adjacent areas where important acts occurred

Overview photographs first and close-up photographs last

The succession of photographs taken at a crime scene is…

False

Overview photographs should include only points of entry and points of exit

Guidelines for the use of digital photography to avoid the possibility of enhancement or doctoring of crime scene photographs

To ensure that their digital images will be admissible, what are many jurisdictions developing?

Computer aided drafting

What programs provide an extensive symbol library and may create a three dimensional sketch?

Rough

What kind of sketch does an investigator need to draw at the crime scene to show its dimensions and pertinent objects?

Systematic matter

A detailed search of the crime scene for physical evidence must be conducted in a…

Physical evidence

What is the crime-scene search undertaken to locate?

False

The search patterns that may be used to search a crime scene for evidence include the line pattern, grid pattern, polar coordinate pattern, and spiral pattern

False

If the investigator does not recognize physical evidence or does not properly preserve it for laboratory examination, sophisticated laboratory instrumentation or technical expertise can salvage the situation and attain the desired results

Trace evidence must be collected for detailed examination in the laboratory

Besides the more obvious items of physical evidence, possible sources of…

Not to be removed from the object that bears it

Whenever possible, trace evidence is…

A separate container

Each item collected at the crime scene must be placed in…

True

An ordinary mailing envelope is considered a good general-purpose evidence container.

An airtight container

What is not recommended packaging material for bloodstained garments?

Air-dried before packaging

As a matter of routine, all items of clothing are to be…

False

Charred debris recovered from the scene of an arson is best placed in a porous container

That a chain of custody be established with respect to the possession and location of physical evidence

What does the possibility of future legal proceedings require?

Standard/reference material for comparison purposes

Most physical evidence collected at the crime scene will require the accompanying submission of…

Provide medical aid to the victim

Secure and isolate the area

Exclude unauthorized persons

Prevent loss or contamination of evidence

Identify and separate witnesses

Maintain the scene until backup arrives

You are the first officer at the scene of an outdoor assault. You find the victim bleeding but conscious, with two of the victim’s friends and several onlookers standing nearby. You call for backup and quickly glance around but see no one fleeing the scene. Describe the steps you would take while you wait for backup to arrive?

1. Two people, small defined area:→ Strip/line or grid pattern

2. Several people, large area:→ Zone or strip/line pattern

3. One person, large area:→ Spiral pattern

What kind of search pattern(s) would investigators be most likely to employ in each of the following situations?

1. Two people searching a small area with well defined boundaries

2. Several people searching a large area

3. A single person searching a large area

He handled and removed evidence before it was photographed

He separated trace evidence from its source

He used a plastic bag, risking moisture retention and degradation

Officer Martin Guajardo is the first responder at an apparent homicide scene. After securing the area, interviewing the sole witness, and calling for backup, he begins to search for evidence. He makes note of a bloody knife lying next to the body, with a small scrap of bloody cloth clinging precariously to the knife. Because it is a very windy day, Officer Guajardo removes the scrap of fabric and seals it in a plastic bag. A few moments later, a crime-scene team, including a photographer, arrives to take over the investigation. What mistakes, if any, did Officer Guajardo make before the crime-scene team arrived?

Properly packaged the shirt in paper

Maintained chain of custody

The forensic scientist correctly resealed and initialed the package after examination

During his search of a homicide scene, investigator David Gurney collects evidence that includes a bloody shirt. After the crime-scene team has completely processed the scene, Investigator Gurney packages the shirt in a paper bag, seals the bag, and labels it to indicate the contents. He then delivers the shirt to the laboratory with an evidence submission form. There, a forensic scientist breaks the seal, removes the shirt, and performs a series of tests on it. He replaces the shirt, discards the old seal, and places a new seal on the package containing his initials and the date on which it was resealed. What mistakes, if any, were made in handling the shirt?

He opened a window, altering the crime scene

He likely concluded the body was moved into the house after death due to lack of blood and struggle evidence

Officer Bill Walter arrives at the scene of an apparent murder: a body bearing several gunshot wounds lies on the floor of a small, un-air-conditioned house in late July. A pungent odor almost overwhelms him when he enters the house, so he opens a window to allow him to breathe so he can investigate the scene. While airing out the house, he secures the scene and interviews bystanders. When he inspects the scene, he discovers very little blood in the room and little evidence of a struggle. What mistake did Officer Walter make in his investigation? What conclusion did he draw about the scene from his observations?