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 place  all 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

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!!!!!