PHYSICAL EVIDENCE MANUAL - Crime Scene Investigator Network

Physical Evidence Manual
Conduct a Detailed Search
Conduct the search of the crime scene using one or more of the following
systematic search approaches.
• Spiral Search: When this crime scene search method is used, the analyst will
start the search at a selected point at the edge of the scene. The analyst will
walk in a circular pattern to the center of the scene, with the circle getting smaller
as they go. This search method is effective in small areas.
• Strip (Lane) Search: When this crime scene search method is used, the analyst
will start the search at the southeast corner of the area to be searched. The
analyst will walk north in a straight line, keeping parallel with the east edge until
he/she reaches the north edge of the scene. At this time, he/she will take two
(2) steps west and walk south in a line parallel to the first path until he reaches
the south edge of the scene. This process is repeated until reaching the west
edge of the scene. This search method works very well when there is a large
area to be searched.
• Zone or Grid Search: When this crime scene method is used, the analyst will
divide the scene to be searched into quadrants. Additional personnel may be
used for this method, or the analyst can perform the search independently. The
personnel searching each quadrant will use any method that they choose. This
method works well with large areas to be searched. In very large search sites
the quadrant may be subdivided to effectively search the crime scene and make
use of all personnel available to perform the search.
• Wheel Search: When this crime scene search method is used, the analyst will
begin the search in the middle of the scene. The analyst will pick out a landmark
and walk in a direct line to it searching the area immediately in front of him/her.
When the landmark has been reached then the analyst will turn and walk the
same path to the originating point. Upon returning to the originating point they
will choose another point of reference and repeat this search method until they
have gone in a complete circle. For obvious reasons, this search method is
effective in small areas.
• Point to Point Search: When this crime scene search method is used, the
analyst will go to the first piece of evidence, process it, then go to the next
apparent piece of evidence, repeating this process until all evidence has been
processed and collected. This search method works well in small or confined
areas.
• Logical Association: this method leads the investigator from one evidence item
to another following a logical progression or evidence trail. Most used by
investigators but requires patient thought, experience, and instinct. This method
is frequently combined with one of the above listed search techniques.
Adopted: May 2002
Revisions: 6
Last Revision: January 31, 2008
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