Crime Scene Investigation

Steps in Crime scene investigation AKA “Processing the Scene”

• Approach scene

• Secure and protect scene to isolate and preserve evidence-CORDON off the area

• Preliminary survey

• Evaluate the scene-”who, what, when, where, why?”

• Objective narrative notes

• Photography

• Sketch

• Search

• Record and collect evidence

• Final survey

Approach the scene

• Responders only use codes when giving and receiving radio information. Example: “10-20” means location. http://www.radiolabs.com/police-codes.html

• Use senses when approaching scene-sight, smell, hearing

• Be aware of safety issues-is anyone armed and dangerous? (only use codes when relaying messages)

• Be prepared to provide emergency service-first aid or call 9-1-1 if you’re first to arrive on scene

Secure and Protect • 1st responders-Cordon off the scene with cordon tape

to protect the integrity of any evidence.

• 1st responders-Detain and separate any suspects or witnesses whenever possible.

• Establish a security log for any and all persons who enter (ingress) or leave (egress) the crime scene.

• Place sentries at all exits

• Keep a detailed log of everyone who enteres or leaves

Survey or “walk-through”

• Examine the exterior/outside of the structure or general area first to look for possible clues

• Look through rooms and sweep the entire crime scene to find connections to crime

• Who is the perpetrator, and who is the victim?

• What happened, when, and why?

• How did the crime happen?

• Where did it happen (the location of the body is not always at the primary crime scene)?

• What is the evidence?

Evaluate the scene Remember every scene is 3-dimensional-look up, down and all around! • Never move the body and only person at a time should examine the body

and surrounding physical evidence Example Questions to be answered in a shooting investigation: • Did the shooting occur in this room • Has the body been moved (by first responders or perpetrator(s) • Has any object been moved (especially by first responders or family

members • Were additional shots besides the one in the victim's head. This means

examining walls, ceiling, room objects, etc. • Are shell casings apparent. If so-mark them with placards, evidence

tents, etc. so they will be obvious in photos. • Are traces of blood apparent in other areas of the room-indicating

movement of the victim • Is blood spatter apparent • Are there signs of a struggle • Are there visible footprints in the blood • Any possible weapons?

The Michigan Murders 1969

Evaluate the scene

• Is it a primary or secondary scene? Is there such thing as a “secondary scene”?

• From a practical perspective-how the “heck” are you going to know where anything occurred on the day the body is found? Primary scene… is where the body is ultimately found and the location where 1st responders were called to. Later if you find details that point to a separate murder location-that location becomes the new primary scene, therefore there isn’t any secondary scene.--Vernon J. Geberth 2010

Narrative Notes • Notes are used in trials—they must be

meticulous and objective!

• Don’t speculate-just the facts!

• Interview 1st responders-did medical teams/police touch or taint any evidence in their attempt to help or secure scene?

Photography

Be certain to have overall, medium range and close-up shots of any potential physical evidence. Be certain to include scales in the close-up shots (CSI.net)

Sketch

2 sketches- rough sketch at the scene and detailed sketch later. An assistant is needed to help with measurements, and it's a good idea is to have this individual verify each measurement to avoid questions later (CSI.net)

ID Victim

IDENTIFY THE VICTIM—Estimate cause, manner, and time of death. Obtain exemplars and controls. Look for ID. Look for drag marks. Note discrepancies in mortis and body temperature.

“Leave no stone unturned”

Why is a detailed search conducted after the sketch and photography as opposed to before?

Evidence Collection • Collect fingerprints and footprints from scene and

from all 1st responders at the scene

• What other “prints” can be found at scene and be used as individual evidence?

• Collect DNA from everyone at scene in addition to possible suspect sources

• Swabbing technique: https://search.yahoo.com/yhs/search?p=crime+seen+swab+samples&ei=UTF-8&hspart=mozilla&hsimp=yhs-001

Evidence Log

• From Casey Anthony case: