Crime Scenes – Sketching the Scene By the end of this lesson you will be able to: 1. Explain the use of a sketch 2. Identify key elements of a sketch 3. Produce a professional crime scene sketch

Step 1 Identify the perimeter of the scene Expand or contract the scene…when would you do either? Be sure that Patrol has setup a perimeter and possibly begun a crime scene log Identify items of evidence

Step 2 Measure and Outline the Area If another officer assists, make sure to reverse the tape so that both officers measure….WHY? Measure from FIXED objects….WHY?

Step 2 - Continued Determine the scale by taking the longest measurement at the scene and dividing the it by the longest measurement on the graph paper IE – Paper is 10 inches and scene is 100 ft, make 1 inch = 10 feet

Step 3 Plot objects and evidence within the sketch Use one of the following methods to plot

Rectangular Coordinate Method Uses 2 adjacent walls as fixed points from which right angles are drawn to a point of evidence within the room or area. Measure from adjacent walls at right angles Use this only when in a square or rectangular area

Triangulation Method Using two fixed points in the scene, record the compass angle from the fixed point using a compass or protractor Best used in outdoor settings

Compass Point Method Also useful in outdoor settings Select one fixed point to measure from and record the distance and the angle from the point

Step 4 Record field notes Include in your notes things not sketchable such as weather, temperature, people present, lighting conditions, time of day, etc.

Step 5 Identify the Scene Construct a legend on the sketch In the legend, include case number, date, time, you name and title, others assisting, scale of the sketch and notate the northern direction

Step 6 Reassess the sketch Check for accuracy Check for legibility Once you leave, you cannot change anything on the sketch File sketch in your Case File