Crime Scene Analysis

Dr. Edmond Locard- The Locard Principal *

“Every contact leaves a trace”

This is the bases of Crime Scene investigations

Forensic Investigations of Crime Scenes: *

  • Requires a wide range of skills and technologies

  • All crime scenes are unique

  • Typically starts with crime scene processing

  • Ultimate success or failure of an investigation begins here

  • Success requires: Recognition, documentation, preservation, and collection

  • You have only one chance to get it right

Case Study: Anthony Terrel Williams:

  • Monday Dec 2nd 2013

  • Damien Reedus officially became the 52nd murder victim in Gary in that year (actually 53rd but other victim was later discovered)

  • 1900 Pennsylvania Ave, Damien was shot in his girlfriends Aja’s Van

  • Aja was also show but was not killed, she escaped and made it to help

  • She reported that she had loaned her van to her boyfriend. It had become late so she called him to bring the van back

  • When Reedus and Williams arrived they were so drunk that Aja decided to drive them home

  • On the way, according to Aja, Williams shot and killed Damian. He then pulled her out of the van and shot her in the neck

  • The gun jammed, Williams fled and Aja ran for help, she was able to name her attacker

  • Police found the van where Aja said, Williams was found a few days later in a motel

What is/are the crime scene/scenes?

  • The environment: The van and the area of ground around it

  • The Body: Aja- her wounds. Damian

  • The motel room where Williams was found

Cont.

  • When last we left the case we had a van, hotel room, Aja’s wounds and Reedus’s body

  • We had eye witness who knew the attacker

  • The expense of scientific examination was not needed so only cursory work was done

  • Here is the problem:

    • Back at the van, blood samples were cross contaminated

    • Only pure sample was from the 4th donor found the next day dead

  • Now, our witness may be an accomplice to another murder

  • He record was not exactly lily white

  • Williams was a known felon, 4 days have elapsed, between incident and Williams arrest

  • No warrant was issued for search for hotel during arrest

  • Photographer was sent in hotel room for initial survey 4 times and found nothing

  • He was eventually told to look between the mattress and found a gun which was matched to Reedus’s wounds

  • Judge excluded gun as being from illegal search (not plain sight)

  • Not notes of the search when the gun was found remained

  • The officer in charge “lost” the file

  • He also quit the force before the case went to trial to go into politics, He had to be arrested and compelled to testify

  • No other physical evidence was collected

  • Only difference in trials was the admission of the gun

  • Juror stated that the gun wasn’t significant it only “put things in context”

  • Bad science ruined investigation and led to multiple trials. Only convicted on an error

Crime scenes:

  • Crime scenes can be any person or place connected to the crime

  • The investigators need to first decided what is relevant and related

First Responder: *

  • Stay safe, establish control and document everything

  • Crime scenes might be indoor, outdoor, or in a vehicle: public or private property

  • Crime scene are further classified according to the type of offense believed to have been committed

  • Properly identifying the type of crime scene will dictate how the investigation must proceed

  • Security, need for a warrant how long a scene might need to be or be able to be held secure, the equipment needed and what safety precaution

Initial actions of a crime scene: *

  • Identify event, what type of crime it?

  • In death investigations: Accident, Homicide, natural or suicide

  • What are the boundaries of the scene

  • Safety first: Check suspect is present

  • Determine if there is a living victim who needs help

  • Evaluate Hazards

  • Secure the scene (Determine Perimeter)

  • Record contrition and people in the area

Hazards: *

  • People or animals intent on doing harm

  • Weapons or items that can be used as weapons

  • Chemicals

Crime scene investigations: *

  • Must obey the 4th amendment

  • “ The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no warrants shall issue, but upon probable cause, supported by oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized

Crime scene investigator: *

  • Surveys and records the scene

  • Collects evidence properly and submits to the lab

  • Usually needs a warrant

Exigent Circumstances (No warrant needed):

  • Prevent harm to officer or others

  • Prevent destruction of evidence

  • Prevent escape of suspect

  • Plain sight

  • Community caretaking and public place

  • Owner consent

Discussion: Mincey vs Arizona:

  • The narcotics part of the Mincey case is what formed the search and seizure appeal to the U.S. Supreme Court. In some places, warrants to search major crime scenes are now called Mincey warrants, a recognition of their compliance with this important Supreme Court decision

Elements of a Mincey Warrant:

  • Identifies what is being searched

  • The justification for the search

  • Proves probable cause

Steps in processing a crime scene: *

Step 1: Initial survey and evidence recognition:

  • Understand what evidence is present

  • Formulate a hypotheses

  • Plan the specific actions for the search

Step 2: Scene searches:

  • A systematic search for any possible evidence should follow in all areas of the scene

  • If no suspect, search should help point to a suspect

  • Type of search depends of crime

Step 3: Documentation:

  • Written record: Case #, date, time, location, person

  • Sketches

  • Photo, videos and 3D scans

Step 4: Evidence Identification:

  • Item given a number and brief description

  • Often marked with a placard and photographed

  • GPS pictures are gaining popularity

Step 5: Collection:

  • Every evidence type has specific methods to use

  • Keep intact when possible

  • Requires training and is governed by SOPs

Step 6: Preservation:

  • Every evidence type has specific containers to use

Collection Examples:

  • Blood can be gathered with a cotton swab

  • Fingerprints can be dusted with carbon black and photographed or collected with tape

  • Tire impressions may be case in plaster

Chain of custody: *

  • All evidence is sealed, documented, and labeled to identify everyone who has handled it

  • This starts at the crime scene and continues as long as evidence is maintained

  • If chain is broken evidence is unavailable to the court

Case Study: Connecticut vs. Richard Crafts:

  • Case was highly circumstantial w/ weak evidence

  • But when it was all taken together made a strong case

  • Does this change your mind as to weather or not all evidence should be examined?

Crime scene analysis and reconstruction:

  • Different from crime scene processing

  • Analysis is the attempt to determine the flow of events

  • There is always the possibility of errors

Reconstruction”

  • These can be done “theoretically” by creating a narrative

  • Physical reconstruction can be built to aid investigators and court in “seeing” the scene

  • Computer simulation can also be used