Photographs and videotapes reproduce the crime scene in detail for presentation to the prosecution, defense, witnesses, judge, and jury in court. They are used in investigating, prosecuting, and police training. Advantages of photographs are that they can be taken immediately, they accurately represent the crime scene and the evidence, they create interest, and they increase attention to testimony. Disadvantages of photographs are that they are not selective, they do not show actual distances, and they may be distorted and damaged by mechanical errors in shooting or processing.
At a minimum, have available and be skilled in operating a 35mm camera, an instant-print or digital camera, a press camera, a fingerprint camera, and video equipment. Digital photography has become the prominent format for recording crime scene information primarily because the information can be stored, analyzed, and distributed via the Internet, which allows experts in disparate locations to collaborate on the evidence/information and provide specialized expertise and experience. The method to record the crime scene using photography is to go from the general to the specific. In other words, the first photograph is of the general area, followed by photographs of specific areas and then specific objects of evidence.
Take exterior shots first because they are the most subject to alteration by weather and security violations. Take photographs before anything is moved or disturbed to avoid inaccuracies and distortions. Types of investigative photography include crime scene, surveillance, aerial, night, laboratory, lineup, and mug shot.
Check out Forensic Photogrammetry at http://www.hgexperts.com/article.asp?id=5220
Check out Laser-beam photography at http://www.ephotozine.com/techniques/viewtechnique.cfm?recid=172
A crime-scene sketch accurately portrays the physical facts. It also relates to the sequence of events at the scene and establishes the precise location and relationship of objects and evidence. It also helps to create a mental picture of the scene for those not present. It is a permanent record of the scene, and it is usually admissible in court.
A crime-scene sketch assists in
- interviewing and interrogating people,
- preparing the investigation report, and
- presenting the case in court
Sketch all serious crime and crash scenes after photographs are taken and before anything is moved. Sketch the entire scene, the objects, and the evidence. Materials for the rough sketch include paper, pencil, long steel measuring tape, carpenter-type ruler, straightedge, clipboard, eraser, compass, protractor, and thumbtacks.
Steps in sketching a crime scene:
- Observe and plan
- Measure distances
- Outline the area
- Locate objects and evidence within the outline
- Record details
- Make notes
- Identify the sketch with a legend and a scale
- Reassess the sketch
An admissible sketch is one drawn or personally witnessed by an investigator that accurately portrays a crime scene. A scale drawing also is admissible if the investigating officer drew it or approved it after it was drawn and if it accurately represents the rough sketch. The rough sketch must remain available as evidence.
Searching is a vital task in most criminal investigations because through searching, evidence of crime and against criminals is obtained. Equally vital, however, is the investigator’s understanding of the laws relating to searches. Every search must be firmly based on an understanding of the restrictions under which police officers must operate. For example, the 4th Amendment to the U.S. Constitution forbids unreasonable searches and seizures.
Check out the case law surrounding the 4th Amendment protections against unreasonable search and seizure at The Fourth Amendment - http://www.privacilla.org/government/fourthamendment.html
To conduct effective searches, criminal investigators must know the legal requirements for searching, the items being searched for, and the elements of the crime being investigated. They must be organized, systematic, and thorough in their searches. A search can be justified and considered legal if any of the following conditions are met:
- A search warrant has been issued
- Consent is given
- An officer stops a suspicious person and believes the person may be armed
- An emergency exists
Technically, according to the 4th Amendment, all searches are to be conducted under the authority of a warrant. To obtain a valid search warrant, police officers must appear before a judge and establish probable cause to believe that the location contains evidence of a crime, and they must specifically describe that evidence. Probable cause is what would lead a person of “reasonable caution” to believe that something connected with a crime is on the premises or person to be searched.
A search warrant can be issued to search for and seize stolen or embezzled property, property designed or intended for use in committing a crime, and property that indicates a crime has been committed or that a particular person has committed a crime. A search conducted with a warrant must be limited to the specific area and specific items named in the warrant. Consent to search must be voluntary, and the search must be limited to the area for which the consent was given.Landmark Search and Seizure Decisions
- The Terry decision established that a pat down or frisk is a “protective search for weapons” and as such must be “confined to a scope reasonably designed to discover guns, knives, clubs and other hidden instruments for the assault of a police officer or others.”
- The Chimel decision established that a search incidental to lawful arrest must be made simultaneously with the arrest and must be confined to the area within the suspect’s immediate control.
A warrantless search in the absence of a lawful arrest or consent is justified only in emergencies or exigent circumstances where probable cause exists and the search must be conducted immediately. The most important limitation on any search is that the scope must be narrowed. General searches are unconstitutional. The exclusionary rule established that courts may not accept evidence obtained by unreasonable search and seizure, regardless of relevance to the case.
The Mechanics of a Search
A successful crime scene search locates, identifies, and preserves all evidence present at the scene. Organizing a search includes dividing the duties, selecting a search pattern, assigning personnel and equipment, and giving instructions. Knowing what to search for is indispensable to an effective crime scene search. Physical evidence is anything material and relevant to the crime being investigated. The elements of the offense/crime help to determine what will be useful as evidence.
Exterior search patterns divide an area into lanes, concentric circles, or zones. Interior searches go from the general to the specific, usually in a circular pattern, covering all surfaces of a search area. The floor should be searched first.