Searching the crime scene

Searching the crime scene

A systematic approach

Searching the scene

• The search for physical evidence must be thorough and systematic

• If the search is not done systematically, and in a timely manner, then charges of negligence or accusations of a cover up may be filed

How to search

• How a crime scene is processed depends largely on the locale and size of the crime scene

• When possible, it is beneficial to have a person for supervising and overlooking of collection procedures

• Some general rules apply to all investigations such as searching for points of entry and exit first and foremost.

How to search

• There are several different methods for collecting physical evidence

• Generally these are chosen based on experience and logic

Spiral search method

Spiral search method

• Generally used for large search areas with very few individuals involved in the search.

Grid search method

Grid search method

• Generally used for large search areas with numerous searchers.

• Often used in open fields and woodland areas

Line search method

Line search method

• Generally used in medium sized search areas with very few searchers.

Quadrant search Method

Quadrant search Method

• Used in small search areas where minute details are very important

Collection of evidence• Evidence must be collected and handled in a way that

prevents any change from taking place between the time it is removed and the time it arrives at the lab.

• Removal of any physical evidence, such as hairs, fibers, soil, etc., should not happen until the evidence is in the lab

• Each different item, or similar items collected at different locations, must placed in separate containers.

Collecting tools

• The tools used in the collection process are as important as the collection itself. – Using the incorrect

tools can result in contamination

• Collection tools also include the packaging devices.– In general manila

envelopes, pill bottles, and cardboard pill boxes are suitable

Collecting blood evidence

• When collecting blood evidence what type of container should you use?

• If you use an airtight container then the condensation is conducive to mold growth and can ruin evidence.

Collecting burned material

• Collection of burned material must be placed in an airtight container because of the possibility of losing volatile substances that could have been used in an arson case.

Chain of Custody

• A written log of where evidence is and who may have it, must be kept at all times.

• Any break in the chain will result in the evidence being inadmissible in court