THE CRIME SCENE

Physical Evidence

• Goals– Define physical evidence– Discuss responsibilities of the first police officer

on the scene– Explain the steps taken for thoroughly recording

the crime scene

Physical Evidence

• As automobiles run on gasoline, crime laboratories “run” on physical evidence.

• Physical evidence encompasses any and all objects that can establish that a crime has been committed or can link a crime and its victim or its perpetrator– Examples- Hair, skin, fibers, fingerprints, blood, DNA,

weapons, soil, glass, documents, etc.

Crime Scene Investigation

• Forensic science is an important element of the total investigative process but is only one aspect, crime labs do NOT solve crimes.

• If the investigator cannot recognize physical evidence or cannot properly preserve it for examination, no amount of sophisticated laboratory instrumentation or technical expertise can salvage the situation.

Crime Scene Investigation

• What needs to be done to avoid crime scene contamination?

• What are the issues

that we would run into

in investigating the scene?

The First Steps

• First priority should be given to obtaining medical attention for individuals in need of it and to arrest the perpetrator if he/she is there.

• As soon as it is possible, extensive efforts must be made to exclude all unauthorized personnel from the scene. – Do you think this would be an easy task?

–Why is this important?

Step 1- Secure the Perimeter

Step 1- Secure the Perimeter

Step 1- Secure the Perimeter

• The first officer to arrive at the scene is responsible for securing the perimeter.– Make the scene large initially– Set boundaries– Look for footprints/ tire tracks– Physical evidence– Perpetrator entrance and exit route

Step 2- Record the Scene

Step 2- Record the Scene

• Using your iPad, please visit the following website;– http://www.forensicmag.com/articles/2009/08/cri

me-scene-photography-capturing-scene

Read the article and answer the following questions-1.) When should the crime scene photographer begin recording the scene?2.) What should the photographer take photos of?

Step 2- Record the Scene

• Photography/video, sketches, and notes are the three methods for crime-scene recording.

• Ideally all three should be employed; however, as is often the case, personnel and monetary limitations may prohibit the utilization of photography at every crime site.

Photography/Video

• The most important prerequisite for photographing/taping a crime scene is for it to be in an unaltered condition.

• Unless there are injured parties involved, objects must not be moved until they have been photographed from all necessary angles.

Photography/Video

• Crime scenes should be photographed/taped as completely as possible – Area in which crime took place• Distant, mid-range and close-up images• “Four corners” of room/structure• Points of entrance and exit

– Bystanders– All adjacent areas– Body positions– Close ups of possible evidence • Show their position and location relative the entire

scene• When the size of an item is of significance, a ruler may

be inserted near the object and included in the photograph as a point of reference.

Sketches

• Once photographs are taken, the crime-scene investigator will sketch the scene.

• Rough Sketch —A draft representation of all essential information and dimensions at a crime scene.

• This sketch is drawn at the crime scene.• It shows all recovered items of physical evidence• Measurements• Includes doors, windows and furniture

Rough Sketch

Sketches

• Finished Sketch —A precise rendering of the crime scene, usually drawn to scale.

• Unlike the rough sketch, the finished sketch is drawn with care and concern for aesthetic appearance.

• Many times your final sketch is completed with CAD

Finished Sketch

Notes

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

• These notes must include a detailed written description with the location of items of physical evidence recovered.

Notes

• They must identify:– The time an item of physical evidence was discovered.– By whom.– How and by whom it was packaged.– The disposition of the item after it was collected.

• Notes may be the only source of information for refreshing one’s memory. (Can be taped and later written)

Recording the Crime Scene

• Investigators have only a short amount of time to work a crime site in its untouched state.

• Every step of the investigation should be recorded thoroughly with an appropriate method.

• Such records will not only prove useful during the investigation but are also useful for presentation at a trial in order to document the condition of the crime site and to show the location of physical evidence.

JonBenet Ramsey Case

• Crime Scene Investigation- Please underline errors made in securing and processing the crime scene.

• Initially, the police conducted a cursory search of the house but did not find JonBenet. The house was not sealed off. Four friends along with the Ramsey pastor were let into the home and allowed to move about at will. John was permitted to leave the premises unattended for an hour and a half. Once hour after his return, John and two of his friends searched the house again. This time John went down into the basement where he discovered JonBenet’s body. He carried her upstairs, placing the body on the living room floor.

Crime Scene Investigation- Please underline errors made in securing and processing the crime scene.