Discussion Question
Sketching
Sketching
Consider sketching to be a floor plan of your scene.
Bird’s eye view (a bird flying over head looking straight down).
Objects, furniture are two dimensional (wide and long) but all are flat (we do not see the legs of furniture for example).
Present a visual aid for where objects, evidence, rooms are located.
Sketches done at the time of the crime scene processing are called rough sketches. These contain the measurements.
A final sketch is cleaned up and without the dimensions on it but the sketch is drawn with those dimensions in mind (example using graph paper if a room is 10 feet by 20 feet in width and length by using 10 squares on grids paper you are drawing the room to its measured size).
Some points
Sketches are two dimensional (width and length).
Drawn as if we are a bird flying over head looking straight down. That means we do not see as if we are standing in the room.
Write in one direction
Have a north directional. Put north at the top of the sketch
Label furniture and areas
Give evidence letters or numbers
Have a legend on the front with the sketch denoting what the letters or numbers means on the sketch. Do not draw shapes.
Keep it simple. Do not have an overwhelming amount of letters.
If you do not have a standard template for the victim or body just write the word victim.
Keep the main thing the main thing.
D
B
A
C
Victim
http://www.forensicmag.com/articles/2014/01/crime-scene-diagramming-back-basics
Legend
A- 9mm FM gun serial #1234
B- 9mm R&P casing
C- 9mm R&P casing
D- possible blood drops
Homicide
04-12-2015
12345 NW King street
Sketch by SPlotkin #253
Not to scale
Final sketch
Courtesy of Jorge Hernandez
Exploded view sketch used when depicting critical evidence on walls. Think of a cardboard box and opening the sides and lying them down…
Computer Sketching Program with Flex-man
Title block
With case
info
Clandestine graves need two views
Bird’s eye
Clandestine graves need two views
Side view
Be sure to include heading (case information)
Diagram area
Legend denoting what your letters or numbers are on the sketch. Do not try and draw objects.
North directional (try and always have north on top).
Also by writing the word victim rather than drawing a body takes away any prejudice or bias.
Not to scale recognizes a degree of error inherent in human beings when taking measurements.
Types of measurements in sketching
Rectangular coordinates- using two permanent walls (exterior which are 10 inches thick rather than interior walls which are 5 inches thick).
Do not use opposite walls. Use an east/ north wall or a south/ west wall when taking measurements and use same two walls to measure everything in that room.
Triangulation
Used when measuring from the corners of a room. The important thing to remember is at what angle you measured as objects may not be in the center of the room.
Baseline coordinates
Great for outdoor use when using a permanent point such as a lamp post (be sure to get lamp post information).
Measure from your lateral line east to west and north to south. Use two tape measures.
Lamp post
North
Grid coordinates
Both rectangular coordinates and triangulation can be used with this.
Used when crime scene is outdoors (burial sites, scattered remains).
A grid is created.
Set a datum, extend a baseline out to the right and up, creating three corners.
Verify the two sides are at right angles using the 3-4-5 rule.
Set the final corner and square it to the opposite sides.
Ross Gardner Practical Crime Scene Processing, CRC Press