Forensic ch 1-3

Comparison analysis

Analysis used for source determination

1. Update the transfer history on the submission sheet 2. Generate a receipt for the transfer

Anytime evidence is passed from one person to another two things must be done.

The depend on him/her to minimize changes in physical evidence so as to maximize it's interpretive value

Describe forensic scientist dependency on the first responding officer

Photos, notes, sketch and audio recordings

Documentation of the crime scene includes

Class characteristics

Evidence that can be associated only with a group

Individual characteristics

Evidence that can be associated with a common source with an extremely high degree of probability

Criminalists

Forensic scientist who interpret physical evidence using applied physical sciences

Sensitivity

How much of ansubstance can be detected by a test

Qualitative analysis

Identification

Undesirable changes of evidence

Loss, contamination, spoilage, breakage

Quantitative analysis

Measurements

Confirmatory tests

More specific than presumptive tests, Because they shows group but more particular and individualized answers.

Establish that a crime has been committed, establish linkages, reconstruct what happened, provide leads for what happened

Physical evidence may help in...

Reconstruction

Putting it all together

4 types of forensic analyses

Quantitative, qualitative, comparison, and reconstruction

Specificity

Refers to how many other samples can be expected to give a positive result in addition to the the substance of interest

Forensics

Refers to rhetorical argumentation debate

Recognize evidence, document crime scene, collect evidence, document the collection process.

Responsibilities of the crime scene search team

Define the crime scene and secure and protect it

Responsibility of the first responding officer is to ...

Presumptive tests

Tests that identify a substance as belonging to a particular group.

Forensic science

The Application of science to the resolution of criminal and civil law as enforced by police agencies in the justice system

Identify problem, Formulating hypothesis, test hypothesis using observations, experimentations, and measurements. Then make a conclusion

The Scientific method inclues

Criminalistics

The application of physical science to physical evidence associated with crime scenes

Physical science (memorize)

The effort to Understand physical phenomena using the scientific method

The circumstances of the crime, thE scientific limitations and the trier of fact

The importance of evidence depends on

Physical evidence

The materials associated with a crime event that may help resolve questions about the crime

Preserve life, control any witnesses or potential suspects and to preserve the secured crime scene

The priorities of the first responding officer is to...

Maintain evidence integrity, and provison of the history of the evidence

The purpose of the chain of custody is to

Calibration

The steps being taken to make sure a test, method or scientific instrument is functioning as designed.

Criminology

The study of criminal behavior

Chain of custody

The written record of the transfer and ownership history of the evidence

1. Mark evidence for future recognition and 2. Provide documentation for historical record.

Two most major steps in the chain of custody are

Locards exchange principle

When two surfaces come into contact with one another, there is a partial re aster of material from one surface to another