Forensic Science 4 part 1

What is the first priority for the first officier at a crime scene?

he is responsible for preserving and protecting the crime scene, however priority should be given to protect himself, obtaining medical assistance for individuals in need and arresting predator (if present). The officer should also detain and seperate witnesses or suspects to record their statements, document everything at the scene and keep a security log.

what are the 7 S’s of a crime scene investigation?

they are key steps that allow to properly process a crime scene; secure the scene, seperate the witnesses, scan the scene, see the scene, sketch the scene, search for evidence, secure and collect evidence

what is the step; secure the scene?

the first responder ensures safety for themselves and others. The responder also restricts access to preserve evidence

what principle is at the heart of crime scene protection, and what does it state ?

Locard’s Exchange Principle. It states that whenever a person comes into contact with a crime scene, they leave pieces of themselves behind and take pieces of the scene with them or they could damage the evidence remaining. That’s why the crime scene must be denied to all unauthorized personnel and a security log is needed.

what does a crime scene include?

• the place where the crime occured

• the exit, entrance and possible escape routes

• places where important pieces of evidence are or could be found

• areas where evidence may have been moved

what is the step, what does it do; separate the witnesses?

it prevents witnesses from colluding or influencing each other’s versions of what happened

what is the step; scan the scene?

there is a need to determine where photos should be taken and what the overall scene looks like

what is the step; see the scene?

Many notes and photographs are taken systematically to document the scene before it is disturbed.

( Investigators only have a limited amount of time to work with the untouched crime scene. This documentation is important for the subsequent investigation and for presentation at a trial.)

What are the 3 main methods of documenting?

notes, photography and sketches. Other methods such as audio and video recording can also be used.

what are notes used to do and how should they be written ?

used to

-describe the crime scene,

-keep track of each piece of evidence

-document each photograph

-record movement of personnel (names, time of arrival)

-record the interview of the first responder to know his or her movements

-make a written description of the body before coroner arrives and moves it

notes written in ink (blue or black) in a bound notebook.

photographs must?

-be taken as soon as possible to preserve the look oof the crime scene (entire scene with wide-angle shots, before and after markers have been placed)

-be taken from all necessary angles before each item is moved (straight above or straight on to illustrate position, including close-ups with reference to track the size of items)

what is the step; sketch the scene ?

a rough, yet detailed sketch is made showing positions of evidence important features of the crime scene

what are rules for crime scene sketches?

• show a compass heading north

• has a scale (1cm=1m)

• written case info must appear in a heading

• must show the relationship of each item of evidence to other items or to the body

• items must be identified with numbers or letters found in a legend

• items must be mapped to show accurate distances from two fixed points

• must be clear and with accurate measurements