CSI Module Two

Evidence Search MethodsWho has not seen a portrayal of a seasoned investigator, wearing a trench coat, kneeling down at a crime scene with a pistol dangling from the end of their pen? How did he find this valuable piece of evidence which seals the fate of the case? Moments before, he was most likely wandering through the crime scene and out of the corner of his eye, caught a glimpse of something metallic under the corner of a chair. “Bingo,” he exclaims, “just what I was looking for!”

Evidence Search Methods

There is a methodical, systematic process that takes place when a crime scene is searched for evidence.

A logical approach is taken, which incorporates various aspects that are known about the present crime scene.

• What type of offense they are investigating• Number of suspects/victims• What types of weapons/implements were used

As the scene unfolds and evidence is found, the approach is altered to provide the most accurate and precise results.

Evidence searching requires mental reconstruction.

Evidence Search Methods

Mental reconstruction is the process of analyzing a crime scene and taking into account items of potential evidence, locations, as well as certain items that are missing and should be sought, all in relation to one another.

Mental Reconstruction

Aspects of a crime scene call for different search methods that are applied to locate areas of interest and potential items of evidence. The decision of which method to follow is less critical than the manner in which the search is conducted. Keep in mind, there is no right way to search a crime scene, but there are many wrong ways.

Evidence Search Methods

An accurate representation of the crime scene is depicted by an investigator’s notes.

Notes are recorded as one of the first means of documentation, prior to photography, sketching, and mapping.

Sometimes, years pass from the date of offense to the date of trial.

Notes can be recalled years down the road, when a case finally goes to trial.

Crime Scene Notes

Some type of representation of a crime scene is needed to refresh your memory as to the condition of the scene upon arrival and the evidence found within the scene.

Detailed notes help to recreate the who, what, when, and where of a crime scene.

More importantly, good note taking practices force the investigator to make observations by recording relevant features and conditions of the crime scene.

Crime Scene Notes

Identifying information is recorded to describe who was involved in an offense.

Many types of identifying information are recorded:

Who:

Names of victims/suspects License platesWitnesses Phone numbersNames on mailboxes at a residence

Addresses

Mailing information Family photographsCompany names  

This information may become valuable at a later time, a time when it is too late to revisit the scene or re-interview the persons at the scene.

An accurate account of the offense can seem fairly obvious to the investigator.

However, the investigation does not end at the scene.

Laboratory staff, medical examiners, coroners, and law enforcement agencies can benefit from the thorough notes taken by an investigator at the scene.

The offense is not the only valuable type of information taken from the scene.

Items, which may or may not be deemed evidence, are noted for further action.

What:

Other items that are recorded to assist in the investigation:

• Item’s condition• What types of processing should be or was performed • Other relevant information

This information is typically documented within the chain of custody, which will be explained in a later unit of this course.

What:

The time of an offense yields potential suspect(s) or consequently rules them out.

An estimated time of death is determined by a medical examiner or coroner, but may not narrow the length of time sufficiently.

Context clues are obtained from the scene which aid in a chronological context.

Items that are irrelevant to the actual offense aid in the determination of a frame of time

• alarm clocks • DVD/VHS players• broken watches • MP3/CD players

When:

Deterioration of items provide insight into possible time of the offense

Deterioration of snow, ice, and common household items such as butter

These items can be tested in a laboratory setting with similar conditions to the crime scene in order to develop a hypothetical time of deterioration.

A warm gun-barrel or cold cup of coffee can provide a relevant window of time that aids in the investigation.

When:

This aspect of note taking may seem like a simple task of writing down an address from a residence

However, throughout the course of an investigation a crime scene may unfold into a complex arena.

May incorporates multiple crime scenes, entry/exit points, and large areas.

Where:

Contemporaneous notes provide an accurate location of where the offense took place, or on the contrary, where the offense did not take place. Street addresses, GPS coordinates, and maps are used to locate an offense.

The location of the actual offense is not the only concern for the investigator.

The location of potential evidentiary items needs documentation.

Where:

It is also important to record evidence that should be present at a particular type of scene, but is not located there.

For example, a victim was shot and there are no bullet casings within the scene.

What does this lead you to believe?

Was the victim shot with a pistol, revolver, or a rifle?

An investigator should take into account the old saying, “Absence of evidence does not imply evidence of absence.”

Where:

Salient factors about a location are gained through instinct as well.

Odors, colors, as well as transient observations like climate, weather, and temperature may help in the ongoing investigation.

Where:

Good note taking is considered an investigator’s best evidence.

It is important to never dispose of original notes, no matter how sloppily written, wrinkled, torn, or stained.

Preservation of original notes is important from a legal and scientific aspect to depict the original condition of the crime scene.

Crime Scene Notes

Another important feature of thorough note taking is chronology.

Keeping notes in order of time and action provides a traceable account of the crime scene.

A way of maintaining chronology is to keep all notes in a bound notebook with numbered pages that have been written in ink.

Therefore, no obliterations or alterations can take place and pages remain sequential.

Crime Scene Notes – Chronology

CSI Module Two