Crime Scene Reconstruction

Crime Scene Reconstruction

I.  Preliminary investigation

1.  2 types of reasoning

a.  Inductive –(S------G) facts put together to create a theory or conclusion

b.  Deductive (G------S) theorize to determine specific facst.

2.  Steps of a preliminary investigation

a.  Interview the lead investigator will inerview the 1st Police officer to arrive at the crime scene in order develop a reconstructionof what happened. Things to determine include how the perpertrator (perp) gained entry, committed the crime, and direction of flight. Ascertain if any medical or emergency personnel were present at the crime scene. Written notes should be taken and include time of notification to respond to crime scene, names and pedigree information of all witnesses.

b.  Examine “the walk through”the crime scene and compare with “theory” developed from initial information. Written notes should be taken and indicate time of day, weather, smells, sounds, and all pertinent information related to the crime scene.

c.  Processing this is completed by trained crime scene technicians or criminalists and includes the following tasks in a particular order.

1.  Photography – to document the crime scene in order to get an overall view and individual evidence.

2.  Sketching- measurements are taken of all pertinent evidence at the crime scene in order to get a “birds eye” view of the crime scene.

3.  Evidence collecting- proper procedure is paramount in order to maintain the chain of custody. Evidence is marked for identification, packaged, and transported to the forensic lab.

II.  Crime Scene Evidence

1.  2 types of evidence found at a crime scene

a.  Testimonial. –statements taken from the victim(s) or witness (es).

Res Gestae statement is a spontaneous statement made at the time of a crime that is closely related to the actions involved in the crime. They are often considered more truthful than later, planned responses.

b.  Physical – material items found at a crime scene.

The value of physical evidence is:

1.  May prove that a crime has been committed

2.  Esablishes any key elements of a crime (mental culpability and unlawful act)

3.  Links a suspect with a crime scene or victim

4.  Establishes the identity of a victim or suspect

5.  Can corroborate verbal statements of a witness

6.  Can exonerate the innocent.

III.  Notetaking and Report Writing

1.  Field Notes- notes taken during a preliminary and follow-up investigation. The purpose of notes is valuable in providing leads, developing facts in a case, and to refresh ones memory. Notes are never fabricated or fictionalized and should include names and addressesof persons mentioned and their relationship to the evidence. Record who? What? Where? When? Why? How?

2.  Report Writing- reports that are typed written and kept in a case file/folder. The report should be;

a.  Factual – contain only relevant facts

b.  Accurate – no inconsistencies

c.  Clear – no confusion

d.  Concise – brief

e.  Complete – who? What? Where? Etc…

f.  Timely – delays can cause loss of evidence, suspects, or witnesses.

3.  The Rosario Rule-all field notes must be retained for the eventuality of a prosecution. Some courts will allow investigators to destroy their notes if it is done in good faith, they are incorporated into the reportand accurately reflect the notes, and the prosecutor turns over the reports to the defense attorney during the “Discovery” phase of a court procedure.

4.  Formats of Note taking

a.  Narrative Style (Victim and/or witness interview)

Shortened version of events as described by the victim or witness, and will be recounted later in amore lengthy report. (ex. Similar to making an outline of facts for writing an essay.

b.  Question and Answer Method (Issuing Miranda)

Ask questions and record the suspects responses, the exact words used. (Advising the suspect of his Miranda rights)

c.  Chronological Approach (Investigations, observations, and fact gathering)

Describe the sequence of events as they had/have occurred. (create a timeline of events for reconstruction of a crime and investigation).

Crime Scene Photography

1.  General Principle – the aim of CS photography is to make a logical story in visual form.

2.  Method

a.  Overlapping – 4 photos per room and exterior going clockwise

b.  Progression – photos move toward a fixed object

i.  General to specific

ii. 3 major vantage points

1.  Long range (LR) – taken at eye range distance and provides an overview

2.  Mid range (MR) – taken 10ft-20ft away and helps establish modus operandi

3.  Close range (Cr) – within 5 ft. and helps establish corpus delecti

3.  Exterior and Interior Shots

a.  Exterior – must use measurements

b.  Interior – not necessary to use measurements (except for bullet holes in walls must be measured)

c.  Markers – numbered yellow tents should be placed next to all evidence at a crime scene

4.  Evidence

a.  3 shots (1 mid range, 2 close range-one with a photographic ruler and one without).

b.  “Fill the Frame” of evidence shots from close range.

c.  Use aphotographic ruler to show perspective and scale

d.  Use ID Tags – log#, case#, investigators name.

e.  Log- a written log of each phototaken w/ pertinent info related to those photos.

5.  Other Procedural Information

a.  Use a 35mm camera (digital/video’s have not been accepted in all courts)

b.  Digital pictures and videography may be used for investigative purposes

c.  “Body Shots” 5 shots should be taken of a dead body. (head to toe, toe to head, left to right, right to left, and 90 degree angle straight down) *optional but important to take a picture underneath the victim

d.  Take photos with reconstruction in mind.

e.  Show objects in relations to a recognized background

f.  Logs and notes should indicate; weather, lighting conditions, time of day, camera position to evidence, type and make of camera, aperture (lens) setting, case number, investigators name.

Crime Scene Sketching

1. Purpose
a. to create a “birds eye” view of the crime scene
b. reveal the spatial relationship between objects
c. refreshes ones memory
d. 2 dimensional
e. provides facts for reconstruction

2. Type
a. Rough draft
i. contains all essential measurements (dimensions, furniture, and evidence location)
ii. Completed at the crime scene with a pencil
iii. Shows all recovered evidence at a crime scene
iv. Distance measured from 2 fixed points
v. tape measure must be used, no estimates – be accurate
vi. Legend/key is used (assign numbers to evidence and letters to furniture)
vii. Include a compass heading (arrow) designating north. (North arrow)
viii. 2 investigators should verify all measurements
b. Finished “smooth” copy
i. precise rendering (drawn to scale)
ii. Completed at a facitlity using a pen, drafting tools or a CAD program
(ex. Smartdraw.com)
iii. Include preparer/assistance names, date, location, weather conditions
3. Scale (size)
CS Scale
Small room 1 foot = ½ inch
Large room 1 ft = 1/4 “
Outdoors 1’ = 1/8”

4. Techniques
a. Rectangular Coordinate measurement method – easiest for indoor crime scenes with 4 walls. Measurements are taken from 2 walls that are abutted to each other.
b. Triangulation method – can be used anywhere indoors but preferably outdoors using to fixed (nonmoveable) objects.
c. Secondary Reference point method
d. Transeecting baseline method
e. Polar coordinate method.

Crime Scene Searches

1. Principles
a. Must thorough and systematic
b. aids in reconstruction
c. areas searched must include all probable points of entry and exit used by perpretrator
d. for homicides the search will center on the weapon or any type of evidence left behind.
e. evidence ranges from trace to large objects.

2. Methods
a. Strip Method (outdoors)
i. large areas
ii. Involves setting up lanes or strips
iii. One searcher per lane
iv. Lanes should not be wider than the area that can be easily seen by each individual searcher.
v. arms length
vi. Mark lanes so not repeated
vii. Good for small items like shell casings

b. Grid method (outdoors) “double strip method”
i. use the strip mehod then turn to right angles
ii. Very thorough
iii. Used in thick grass
iv. Searches can go on their hands and knees
v. although time consuming, it ensures no items are missed.
vi. Good for trace evidence (hair, glass, blood)

c. Zone Method (indoors)
i. divides crime scene into zones or sectors
ii. Zones can be subdivided
iii. Good for locating bloodstain patterns, firearm projectile trajectories, and other evidence.

D. Spiral Method (outdoor)
i. start in the center and work your way out in a spiral
ii. Not recommended for indoors or small outdoor crime scenes
iii. Good for large outdoor scenes where searcher is looking for very large objects that are very
to see, however hindered by tall grass/objects. (ex. Searching for a dead body).

Evidence Collection

1.  Principle

a.  All objects in the universe are unique (All evidence has potential value)

b.  Locard Exchange Principle therefore proper precautions should be taken

i.  Protective clothing such as booties, gloves, masks, and dsiposable “tyvek” suits should be worn to prevent contamination.

2.  Method
a. All items should be photographed before collecting.
b. All items should be marked for identification with collector’s initials and date.

c.  All items should be properly packaged
i. trace evidence should be double packaged.
ii. Wet/ perishable items should be dried, and placed in paper wrap/bags.
iii. Bloody items wet or dry should be packaged in paper not plastic.

iv. all packages should be properly sealed with tape, initialed, and dated.

d.  Chain of Custody sticker should be attached to package and properly filled out.

e.  A Request for Lab Analysis form should be filled out and attached to package.

f.  Property should be transferred to the property clerk (property person) and vouchered. The evidence will then be transported to the proper department in the crime lab for analysis.

g.  The hands of a homicide victim should be “bagged” to protect for trace evidence.

h.  Items to be processed for fingerprints should not be wrapped in paper or cloth and proper care should be used to prevent latent fingerprints from being destroyed.

i.  Homicide victims should be brushed for trace evidence by using clean white paper and placing next to victim, who will be brushed. In unable to complete this at the crime scene the victim can be wrapped in a clean white sheet to safeguard from contamination from the body bag.