Santa Rosa Police

Field and Evidence

Technicians (FET)

Who are we and what do we do?

Training

16-24 week training program with Field and

Evidence Technician Trainers

Basic Crime Scene Investigator

Certification (2 week course)

Basic and Intermediate Traffic Investigation

(one week each)

What does a Field and Evidence

Technician (FET) do?

We are not “CSI” as seen on TV!

Routine calls for service

A day in the life of a FET

Briefing

Equipment check

Log on

Answer calls for

service

Anything from found

property to a homicide

scene

What is a Crime Scene?

Crime scenes can include…

Crime Scene Security…

Crime Scene Processing…

The documentation of the crime scene in it’s condition when first found.

Forms a picture of what occurred.

The information will be used in the investigation to link the suspect to the victim and to the crime scene.

All “types” of documentation could eventually be used in court as a re-creation for the judge and jury of how the crime scene appeared immediately after it was found by police.

Types of Documentation

Photography/Videotaping

Written notes

Measurements

Photography

Written Documentation

➢ Field officer’s notebook (briefing notes/ Hot

Sheet/Stop and Holds/PAL’s/FI’s)

➢ Steno notepad (daily calls for service notes)

- Who, What, When, Where, Why and How?

➢ Crime Scene Notes, which can include

checklist(s), sketches, measurements, facts such as

weather, temperature, and detailed descriptions.

Types of Written Documentation

Measurements

Measurements are taken to accurately

document their spatial relationship to

structural and evidentiary items.

To document their position in space and

time.

Diagrams are drawn from the measurements

to create another factual depiction of the

scene.

Measuring devices include…

Photography rulers

Steel tape

Roll-a-tape

Large scale rulers (for walls, ground, etc.)

Electronic Measuring device

Total Station (for outdoor scenes)

Measuring Devices at work…

Rough sketch

Hand Drawn Diagram

Visio Diagram

Traffic Diagram

What is evidence?

Evidence can be physical, circumstantial or

testimonial. Any one of these can be used

to prove or disprove fact. The CSI searches

for clues to gain explicit knowledge of the

series of events that surround the

commission of a crime.

The Transfer Theory

Every suspect that

enters the crime scene

brings something into

that scene and takes

something from it.

This assists us in

proving or disproving

that the suspect/victim

are linked to the scene.

Evidence can include, but is not

limited to…

Weapons

Fingerprints

Shoe sole impressions

Tire impressions

Dental impressions

Tool marks

DNA

Trace

Evidence Items

Trace Evidence

Hair

Fibers

Dirt

Chemicals

Scent

Paint

Glass

How is evidence identified and

collected?

This is a combined effort with the first

officers on scene, the detectives, and

information gleaned from interviews.

We then rely on our collective training and

experiences to ascertain what is necessary

evidence to be documented and collected.

Evidence Collection

Evidence can be collected in many ways.

Our utmost concern is preservation.

Cross contamination is also a concern.

(Thanks OJ!)

Personal Protective Equipment (gloves,

tyvek, anti-putrefaction suits, etc).

Packaging material

Protective Clothing

Fingerprints

What are fingerprints?

How are they left behind?

How can FET’s find them?

What do FET’s use to develop the prints?

How do FET’s collect them?

How are they used?

Lifted print Rolled print

Alternate Light Source

What is it?

What do FET’s use it for?

* DNA

* Fingerprints

* Trace Evidence

ALS used on a Human Body

Examples of impression evidence

More impression evidence…

More still…

Death Investigations

Homicide

Suicide

Natural

Accidental