Crime SceneProcessing 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 SceneResponsibility?
Secure and Isolate ContOnce the scene is secured, lead investigator establishes:
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 SceneThe three methods of recording the scene are done in the following manner:
Record Scene: PhotographyPhotographythe 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: PhotographyWhat should be photographed?
Record Scene: PhotographyWhat should be photographed? Cont
Record Scene: PhotographyClose-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 stateStill photography is still the best for its detail
Record Scene: Rough Sketchesafter photos, the investigator will sketch the scene (see diagram)
Record Scene: Rough SketchWhy?
Rough Sketch ContAll objects are measured from two fixed points ( ) 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 itemThe sketch should always designate North
Rough Sketch Cont
Record Scene: Finished SketchA 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: NotesNote 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 recoveredMust 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 collectedTape recording notes is a helpful tool, but at some point the tape must be transcribed
Searching the SceneTypes 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 ContThe 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 victimClothing 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
Searching ContThe following items obtained from the body should be sent to the lab for testing:
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 labHairs, 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 ContBlood stains can be removed by either scraping and transferring to a moistened swab or cutting out the stainEACH 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 ContBlood (and all clothing) SHOULD NEVER be packaged in an air-tight plastic containerWhy?
Any charred debris SHOULD be packaged in an air-tight containerWhy?
Maintaining a Chain of CustodyContinuity of possession (chain of custody) must be established whenever evidence will be presented in courtEVERY PERSON WHO HANDLED THE EVIDENCE MUST BE ACCOUNTED FOR!!!!Evidence is carefully packaged and marked at the crime scene (collectors initials, date of collection, location of evidence)
Chain of Custody ContWhenever a transfer of evidence occurs it must be recordedChain of custody should be kept to a minimum
Obtain ControlsWhen possible, any collected evidence (hair, fibers, soil, etc.) should be compared with a control (known sample) from the actual crime sceneBloodstain 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 testedCase history should accompany the evidence submission form so the analyst can examine the evidence in a logical sequenceThe particular type of test should be noted, but analyst is not bound only to that test
Submitting Evidence ContEach 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 SceneAny evidence at the scene must be removed in compliance with 4th Amendment privileges.Allowances for a warrant-less search:
Legal Allowances Cont
Mincey v. Arizona under the pretext of buying drugs, police forced entry into Rufus Minceys apartment and an undercover officer was killed over a 4 day period police gathered evidence without a warrantMincey was convicted but appealed saying the evidence was collected without a warrant or his consent
Mincey v. Arizona Cont
Michigan v. Tyler a fire burned down Tyler and his partners businesspolice were prevented from immediately searching the scene due to smoke, darkness, etc.the next morning evidence was collected and removed
Michigan v. Tyler Cont4, 7, and 25 days later more evidence was collected without a warrant and was used to convict Tyler and his partner of arsonThe Supreme Court says.
Court Case ConclusionThe Moral of the Story:OBTAIN A SEARCH WARRANT BEFORE INVESTIGATING AND COLLECTING PHYSICAL EVIDENCE!!!!!