Crime Scene Diagramming Flashcards
What are 3 purposes of crime scene sketches?
1) Showing scene layout
2) Illustrating spatial relationships
3) Clarifying objects/features from notes/photos
A sketch will depict possible paths of (HINT: 3 things)…
Entry, exit, and movement through the scene
In what 3 situations will you have to create a sketch?
1) Violent crimes
2) Crimes against children
3) Death investigation
What 5 items should you include in your rough sketch?
1) Title block
2) Legend
3) Compass
4) The diagram itself
5) Points of reference
Should you fix the evidence or the scene first?
Evidence
What does it mean to “fix the evidence?”
Establishing an object’s in-situ location/position
Why is it important to fix the evidence first, before the scene?
To minimize the likelihood of accidentally moving an item before its documented
When fixing your evidence, how many times minimum should you measure where the evidence is?
Twice
What does a bird’s eye view sketch detail?
The entirety of the scene from an aerial view
What does a cross projection (exploded) sketch detail?
The entirety of the scene, similar to the bird’s eye view, but the walls are drawn flat on the ground
What does an elevation sketch detail?
Various points of elevation from a sideways view
Elevation sketches are useful in determining…
Bullet trajectory
What does a three-dimensional sketch detail?
Quite literally a 3D model of the scene
Why is it better to use a measurement log instead of writing your measurements on your rough sketch?
The rough sketch gets too messy eventually
What types of scenes is rectangulation most suited for?
Scenes with defined boundaries, such as a room or house
How is evidence fixed via rectangulation?
You measure the evidence at right angles from the evidence to the surrounding walls
How is evidence fixed via triangulation?
You take 2 line measurements from 2 distinct landmarks to one point on the evidence to form a triangle (be sure to repeat this for 2 fixed evidence points)
What are the best 2 environments for a transecting baseline measurement?
1) Outdoor scenes
2) Very large indoor rooms
Can you randomly choose a baseline for a scene?
No. The baseline should be set and repeatable
What 2 measurements are needed to create a baseline?
1) Length of the baseline itself
2) Length 90 degrees off the baseline
When getting the 90 degree measurement from the baseline, you should…
Note the cardinal direction
What tool does the polar coordinate measuring style use?
Azimuth circle
What type of scene is the azimuth circle best used for?
Outdoor scenes with largely scattered evidence
When using the azimuth circle, which direction should the 0-degree mark be positioned?
North
What 3 tools does the total station measurement style use?
1) Automatic transits
2) Lasers
3) Computers
What is a pro of the total station measuring style?
It is the most accurate and easy to translate into a final sketch
What is a con of the total station measuring style?
It’s very expensive
Should a finished sketch be drawn to scale?
Yes
What do CAD programs do?
Create 3D finished sketches
What does CAD stand for?
Computer-Aided Drafting
