Evaluate the current legal ramifications of crime scene searches (e.g., obtaining of search warrants).
Discuss upcoming search with involved personnel before arrival at scene, if possible.
Select, when feasible, person-in-charge prior to arrival at scene.
Consider the safety and comfort of search personnel — do not be caught unprepared when encountering a potentially dangerous scene or inclement weather — examples are:
Organize communication with services of an ancillary nature (e.g., medical examiner, prosecutive attorney) in order that questions which surface during crime scene search may be resolved. Take
steps to organize a "command post" headquarters for communication, decision-making, etc., in major/complicated investigations.
Basic Stages in a Search
Approach scene Secure and protect scene
Initiate preliminary survey/determine scene boundaries
Evaluate physical evidence possibilities
Prepare narrative description
Depict scene photographically
Prepare diagram/sketch of scene
Conduct detailed search
Record and collect physical evidence
Conduct final survey
Release crime scene
Be alert for discarded evidence
Make pertinent notes as to possible approach/escape routes
Secure and Protect Scene
Take control of scene on arrival.
Determine extent to which scene has thus far been protected.
Ensure adequate scene security.
Obtain information from personnel who have entered scene and have knowledge relative to its original conditions — document who has been at scene.
Take extensive notes — do not rely on memory.
Keep out unauthorized personnel — begin recording who enters and leaves.
Initiate Preliminary Survey
The survey is an organizational stage to plan for the entire search.
A cautious walk-through of the scene is accomplished.
Person-in-charge maintains definite administrative and emotional control.
Delineate extent of the search area — usually expand initial perimeter.
Organize methods and procedures needed recognize special problem areas.
Determine personnel and equipment needs make specific assignments.
Identify and protect transient physical evidence.
Develop a general theory of the crime.
Make extensive notes to document scene physical and environmental conditions, assignments, movement of personnel, etc.
On vehicles get VIN number, license number, position of key, odometer reading, gear shift position, amount of fuel in tank, lights turned on or off.
Evaluate Physical Evidence Possibilities
Based upon what is known from the preliminary survey, determine what evidence is likely to be present.
Concentrate on the most transient evidence and work to the least transient forms of this material.
Focus first on the easily accessible areas in open view and progress eventually to possible out-of-view locations — look for purposely hidden items.
Consider whether the evidence appears to have been moved inadvertently.
Evaluate whether or not the scene and evidence appears intentionally "contrived".
Prepare Narrative Description
The purpose of this step is to provide a running narrative of the conditions at the crime scene. Consider what should be present at a scene (victim's purse or vehicle) and is not observed and what is out of place (ski mask).
Represent scene in a "general to specific" scheme. Consider situational factors: lights on/off, heat on/off, newspaper on driveway/in house, drapes pulled, open or shut.
Do not permit narrative effort to degenerate into a sporadic and unorganized attempt to recover physical evidence — it is recommended that evidence not be collected at this point, under most circumstances.
Methods of narrative — written, audio, video.
Begin photography as soon as possible — plan before photographing.
Document the photographic effort with a photographic log.
Insure that a progression of overall, medium and close-up views of the scene is established.
Use recognized scale device for size determination when applicable.
When a scale device is used, first take a photograph without the inclusion of this device.
Photograph evidence in place before its collection and packaging.
Be observant of and photograph areas adjacent to the crime scene — points of entry, exits, windows, attics, etc.
Consider feasibility of aerial photography.
Photograph items, places, etc., to corroborate the statements of witnesses, victims, suspects.
Take photographs from eye-level, when feasible, to represent scene as it would be observed by normal view.
Film is relatively cheap compared to the rewards obtained — do not hesitate to photograph something which has no apparent significance at that time — it may later prove to be a key element in the investigation.
Prior to lifting latent fingerprints, photographs should be taken 1:1, or use appropriate scale.
Prepare diagram/sketch of scene
The diagram establishes permanent record of items, conditions, and distance/size relationships — diagrams supplement photographs
Rough sketch is drawn at scene (normally not drawn to scale) and is used as a model for finished sketch.
Typical material on rough sketch:
Scale or scale disclaimer
Key or legend
Number designations on sketch can be coordinated with same number designations on evidence log in many instances.
General progression of sketches:
Lay out basic perimeter
Set forth fixed objects, furniture, etc.
Record position of evidence
Record appropriate measurements — double check
Set forth key/legend, compass orientation, etc.
Conduct Detailed Search/Record, and Collect Physical Evidence
Accomplish search based on previous evaluation of evidence possibilities.
Conduct search in a general manner and work to the specifics regarding evidence items.
Use of specialized search patterns (e.g., grid, strip/lane, spiral) are recommended when possible.
Photograph all items before collection and enter notations in photographic log (remember — use scale when necessary).
Mark evidence locations on diagram/sketch
Complete evidence log with appropriate notations for each item of evidence.
Ensure that evidence or the container of evidence is initialed by investigator collecting the evidence.
Do not handle evidence excessively after recovery.
Seal all evidence containers at the crime scene.
Do not guess on packaging requirements different types of evidence can necessitate different containers.
Do not forget entrance and exit areas at scene for potential evidence.
Be sure to obtain appropriate "Known" standards (e.g., fiber sample from carpet).
Constantly check paperwork, packaging notations, and other pertinent recordings of information for possible errors which may cause confusion or problems at a later time.
Four basic premises:
The best search options are typically the most difficult and time consuming.
You cannot "over-document" the physical evidence.
There is only one chance to perform the job properly.
There are two basic search approaches, in this order:
A "cautious" search of visible areas, taking steps to avoid evidence loss or contamination.
After the "cautious" search, a vigorous search for hidden/concealed areas.
Conduct Final Survey
This survey is a critical review of all aspects of the search.
Discuss the search jointly with all personnel for completeness.
Double check documentation to detect inadvertent errors.
Check to ensure all evidence is accounted for before departing scene.
Ensure all equipment used in the search is gathered.
Make sure possible hiding places of difficult access areas have not been overlooked in detailed search.
Critical issues: have you gone far enough in the search for evidence, documented all essential things, and made no assumptions which may prove to be incorrect in the future?
Release Crime Scene
Release is accomplished only after completion of the final survey.
At minimum, documentation should be made of :
Time and date of release
To whom released
By whom released
Ensure that appropriate inventory has been provided as necessary, considering legal requirements, to person to whom scene is released .
Once the scene has been formally released, reentry may require a warrant.
Only the person-in-charge should have the authority to release the scene. This precept should be known and adhered to by all personnel.
Consider the need to have certain specialists serve the scene before it is released (e.g., blood pattern analysts, medical examiner).
This information was adapted from the California Commission on Peace Officer Standards and Training's workbook for the "Forensic Technology for Law Enforcement" Telecourse presented on May 13, 1993. Please see the acknowledgments.