Crime Scene Processing the Crime Scene
Crime Scene
Processing the Crime Scene
Processing the Crime Scene
“Physical evidence encompasses any and all objects that can establish that a crime has been committed or can provide a link between a crime and its victim or a crime and its perpetrator.”
Secure and Isolate the Crime Scene
Responsibility?
Only authorized personnel should be allowed on the scene
Every person who enters the scene is a potential destroyer of viable physical evidence
Secure and Isolate Con’t
Once the scene is secured, lead investigator establishes: boundaries of the scene perpetrator’s path of entrance and
exit documentation of photographs of
physical evidence strategy for systematic examination
and documentation of entire crime scene
Record the Scene
Since the crime scene will not remain in its original state for very long, a permanent record of the scene must be made as soon as possible. These records are also required at trial.
Record the Scene
The three methods of recording the scene are done in the following manner: Photography Sketching the scene Note-taking
Record Scene: Photography
Photography the scene should be
photographed in an unaltered condition. Unless someone is injured, everything should be left in its original condition until all evidence is photographed.
Record Scene: Photography
What should be photographed?area the crime took placeall adjacent areas where acts
occurred immediately before or after the crime
points of entrance and exit if a body is present, photos should
be taken to show position and location relative to the entire scene
Record Scene: Photography
What should be photographed? Con’t close-ups of injuries and
weapons are necessary After removal of body,
photos of the area underneath the body should also be taken
Record Scene: Photography
Close-up Photos of Physical Evidence with a ruler or something else to show size/scale (point of reference)
Videotaping/digital cameras can also enhance the preservation of the evidence in its original state
Still photography is still the best for its detail
Record Scene: Rough Sketches
after photos, the investigator will sketch the scene (see diagram)
Record Scene: Rough Sketch
Why? First a rough sketch is made at the scene
containing accurate depiction of the dimensions at the scene and the location of important objects to the case (body, weapon, etc.)
Rough Sketch Con’t
All objects are measured from two fixed points (triangulation method) accurately with a tape measure (NOT GUESS)
Each object is then given a letter and a legend or list will correlate the letter to the item
The sketch should always designate North
Rough Sketch Con’t
Record Scene: Finished Sketch
A finished sketch will be made from the rough sketch and will then be drawn to scale using the measurements provided in the rough sketch. (This is what will be used as evidence in court.)
Record Scene: Notes Note taking is a constant activity throughout
the processing of the crime scene and include: Detailed written description of the
scene with the location of physical evidence recovered
Must identify the time the evidence was discovered, by whom, how and by whom it was packaged and marked and disposition of the item after it was collected
Tape recording notes is a helpful tool, but at some point the tape must be transcribed
Searching the Scene
Types of Searches (See Diagram) – searches at the crime scene must be systematic and the type of search will be determined by locale and size of the area and actions of victim and suspect at the scene
Searching the Scene
Searching Con’t
The physical evidence that should be collected include hairs, fibers, blood, glass, soil, fabric impressions (in a car or on furniture)
Particular attention is paid to cross-transfer of evidence between the perpetrator and the weapon and/or victim
Clothing from the suspect may be collected and must be bagged separately
Areas of the crime scene may be vacuumed and the sweeping submitted to the lab for testing
Vacuum Equipment
Searching Con’t The following items obtained from the body
should be sent to the lab for testing: Victim’s clothing Fingernail Scrapings Head and pubic hairs Blood Vaginal, anal, penile, oral swabs
(in sex-related crimes) Bullets recovered from body Hand swabs from shooting
victims
Collect and Package Physical Evidence
Physical evidence must be collected in such a way that prevents any change between the crime scene and the crime lab Hairs, blood and fibers should not be
removed at the scene. The article it is on should be sent to the lab intact and the evidence removed there.
Collect and Package Con’t
Blood stains can be removed by either scraping and transferring to a moistened swab or cutting out the stain
EACH DIFFERENT ITEM MUST BE PACKAGED SEPARATELY!!!
Many materials can be used to package evidence – plastic pill bottles, manila envelopes, and vials etc.
Collect and Package Con’t
Blood (and all clothing) SHOULD NEVER be packaged in an air-tight plastic container Why?
Any charred debris SHOULD be packaged in an air-tight container Why?
Maintaining a Chain of Custody
Continuity of possession (chain of custody) must be established whenever evidence will be presented in court
EVERY PERSON WHO HANDLED THE EVIDENCE MUST BE ACCOUNTED FOR!!!!
Evidence is carefully packaged and marked at the crime scene (collector’s initials, date of collection, location of evidence)
Chain of Custody Con’t
Whenever a transfer of evidence occurs it must be recorded
Chain of custody should be kept to a minimum
Obtain Controls
When possible, any collected evidence (hair, fibers, soil, etc.) should be compared with a control (known sample) from the actual crime scene
Bloodstain evidence must be accompanied by whole blood or buccal swab controls which are obtained from all relevant crime scene participants
Submitting Evidence to the Lab
Evidence submission forms are required for all articles to be tested
Case history should accompany the evidence submission form so the analyst can examine the evidence in a logical sequence
The particular type of test should be noted, but analyst is not bound only to that test
Submitting Evidence Con’t
Each item for testing must be listed, packaged separately and assigned a number or letter
Crime Scene Safety – (see guidelines)
See text pgs 47 - 50
Legal Considerations at the Crime Scene
Any evidence at the scene must be removed in compliance with 4th Amendment privileges.
Allowances for a warrant-less search: the existence of emergency
circumstances the need to prevent the immediate
loss or destruction of evidence
Legal Allowances Con’t
a search of a person or 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
Mincey v. Arizona
under the pretext of buying drugs, police forced entry into Rufus Mincey’s apartment and an undercover officer was killed
over a 4 day period police gathered evidence without a warrant
Mincey was convicted but appealed saying the evidence was collected without a warrant or his consent
Mincey v. Arizona Con’t
The court upheld Mincey’s position stating that the police had time to obtain a warrant since Mincey was in custody
Michigan v. Tyler
a fire burned down Tyler and his partner’s business
police were prevented from immediately searching the scene due to smoke, darkness, etc.
the next morning evidence was collected and removed
Michigan v. Tyler Con’t
4, 7, and 25 days later more evidence was collected without a warrant and was used to convict Tyler and his partner of arson
The Supreme Court overturned the decision stating the evidence collected that morning was proper and did not need a warrant but the additional entries did require a warrant
Court Case Conclusion
The Moral of the Story: OBTAIN A SEARCH WARRANT BEFORE
INVESTIGATING AND COLLECTING PHYSICAL EVIDENCE!!!!!