Observation & Documentation

1. The forensic examiner must be able to find—identify the evidence.

2. The forensic examiner must be able to document—record the evidence.

3. The forensic examiner must be able to interpret—accurately determine the significance of the evidence.

What is Observation?

(click picture)

Our brains can filter out information.

What is Observation?Our brains fill in gaps in our perception.

• In order to make sense of what we perceive, our brains often enrich with detail what we see, taste, hear, smell, or feel.

• After an event, we can believe things were part of the background even though they were not.

What is Observation?

How observant are you?

Questions About Suspects

1. Describe the picture in as much detail as you can.2. How many people are in the picture?3. What was the height of the tallest and shortest

person? 4. What colour shoes is the person with the tie wearing?5. What type of the hat is the person on the right

holding?6. How many people have their hands crossed?

Eyewitness Accounts

Eyewitness reports can vary significantly• Barry C. Scheck and Peter J. Neufeld at the

Benjamin N. Cardozo School of Law, starting in 1992, use DNA to examine post-conviction cases.

• The project has found that up to 87% of the wrongful convictions they discovered were due to faulty eyewitness identifications.

Eyewitness Accounts• What What factors effects eyewitness observations?

How to be a Good Observer?Observe systematically— • Start at one part of a crime scene and run

your eyes slowly over every space. • Slowly look at every part of a piece of

evidence. • Do not assume that later on you will be able

to remember everything.

How to be a Good Observer?Turn off filters— • Do not pay attention to only what you think

is important. • On a crime scene you will not know what will

turn out to be important. • Make a conscious effort to pay attention to

all the details in your surroundings.

How to be a Good Observer?Leave the final interpretation of data until

later— • Do look for patterns and make connections. • But the more information obtained, the better

will be the interpretations. • Remember that eyewitness accounts and

your own thinking can include prejudices.

How to be a Good Observer?Documentation, documentation, documentation—

Summary

• The environment and our natural sensory filters affect our ability to observe.

• Eyewitness reports can be faulty. • Gaining good observation skills is possible. • Forensic scientists find, document, and

accurately interpret the evidence.

Arriving at a Crime Scene

1. The crime scene is first secured by a uniformed police officer.It is critical that no evidence is disturbed.

Arriving at a Crime Scene2. The scene is then most likely examined by

the senior detective who is in charge of the investigation

3. Specialist crime scene investigators (CSI’s) look for evidence.

Arriving at a Crime Scene

3. Police photographer will take still photography and video.

• This can be used by forensic analysts or in court.

• Photos are takenfrom multiple angles using a forensic ruler

Arriving at a Crime Scene

4. Often a police draughtsmen will sketch the site.

Arriving at a Crime Scene

• CSI’s wear gloves, overalls and overshoes to avoid contaminating evidence.

• A thorough search can take hours to ensure nothing is missed.

Removing the Evidence

• Evidence is “bagged and tagged” for analysis using Chain of Custody forms and evidence indicators.