Forensic Science An Introduction to Scientific and Investigative Techniques Stuart H. James and Jon J. Nordby Chapter 1 CRC Press: Forensic Science, James and Nordby, 3rd Edition

Chapter 1 Here We Stand: What a Forensic Scientist does. Chapter Author: Jon J. Nordby Presentation created by Greg Galardi, Peru, Nebraska Edited by Stuart H. James, Fort Lauderdale, Florida and Dan Mabel, Richmond, Virginia Chapter 1 CRC Press: Forensic Science, James and Nordby, 3rd Edition

Here We Stand:

What a Forensic Scientist does.

Chapter Author: Jon J. Nordby

Presentation created by Greg Galardi, Peru, Nebraska

Edited by Stuart H. James, Fort Lauderdale, Florida and

Dan Mabel, Richmond, Virginia

Requirements of a Forensic Scientist Ability to reason during times when human emotion may attempt to override rationality Ability to be rational in applying tenets of forensic science to real life human situations Ability to address life’s grimmest realities while maintaining human feelings Chapter 1 CRC Press: Forensic Science, James and Nordby, 3rd Edition

Ability to reason during times when human emotion may attempt to override rationality

Ability to be rational in applying tenets of forensic science to real life human situations

Ability to address life’s grimmest realities while maintaining human feelings

Forensic Scientists May recover human remains Identify human remains Document the cause of human death Assist in criminal investigations through scientific analysis of evidence Chapter 1 CRC Press: Forensic Science, James and Nordby, 3rd Edition

May recover human remains

Identify human remains

Document the cause of human death

Assist in criminal investigations through scientific analysis of evidence

Forensic Scientists Contribute scientific reliability in court, which may Ensure the guilty receive punishment Free innocent people Provide a method to correlate a measurement of scientific reliability with a specific facet of forensic science Chapter 1 CRC Press: Forensic Science, James and Nordby, 3rd Edition

Contribute scientific reliability in court, which may

Ensure the guilty receive punishment

Free innocent people

Provide a method to correlate a measurement of scientific reliability with a specific facet of forensic science

Law and Forensic Science Forensic scientists are independent finders of fact Most operate under police jurisdiction or administration Have a duty to strike a balance between duties of job and results of tests Must be committed to ethical behavior Must be able to distinguish reliable from unreliable scientific practice Chapter 1 CRC Press: Forensic Science, James and Nordby, 3rd Edition

Forensic scientists are independent finders of fact

Most operate under police jurisdiction or administration

Have a duty to strike a balance between duties of job and results of tests

Must be committed to ethical behavior

Must be able to distinguish reliable from unreliable scientific practice

Law and Science Forensic Scientists should Use all relevant testing to discern truth Define “scientific error” categorically, not personally Be adaptable and advance the common good Understand that courts often resolve applications of the legal issues surrounding forensic science Chapter 1 CRC Press: Forensic Science, James and Nordby, 3rd Edition

Forensic Scientists should

Use all relevant testing to discern truth

Define “scientific error” categorically, not personally

Be adaptable and advance the common good

Understand that courts often resolve applications of the legal issues surrounding forensic science

Lawyers and Forensic Scientists Both lawyers and forensic scientists have legal and moral obligations Both focus on determining the truth or circumstances surrounding a crime Law is outcome based, while science is justification based Evidence and it’s admissibility play a critical role in determining truth Chapter 1 CRC Press: Forensic Science, James and Nordby, 3rd Edition

Both lawyers and forensic scientists have legal and moral obligations

Both focus on determining the truth or circumstances surrounding a crime

Law is outcome based, while science is justification based

Evidence and it’s admissibility play a critical role in determining truth

Theoretical Natural Sciences and Practical Forensic Sciences Forensic Scientists, unlike their counterparts, must become familiar with lawyers and the law Forensic Scientists must combine scientific skills with a sworn duty to the public good Forensic Science = Public Science Chapter 1 CRC Press: Forensic Science, James and Nordby, 3rd Edition

Forensic Scientists, unlike their counterparts, must become familiar with lawyers and the law

Forensic Scientists must combine scientific skills with a sworn duty to the public good

Forensic Science = Public Science

Natural vs. Forensic Science Natural Sciences Theoretical Pure Knowledge Orderly Pristine Controlled General Covering Laws Predictions Certain Forensic Science Practical Applied to problems Disorderly Contaminated Chaotic Specific Approximations Conjectures Uncertain Chapter 1 CRC Press: Forensic Science, James and Nordby, 3rd Edition

Natural Sciences

Theoretical

Pure Knowledge

Orderly

Pristine

Controlled

General

Covering Laws

Predictions

Certain

Forensic Science

Practical

Applied to problems

Disorderly

Contaminated

Chaotic

Specific

Approximations

Conjectures

Uncertain

Theoretical Natural Sciences and Practical Forensic Sciences Ceteris Paribus Laws “ Other things being equal” Scientists use the Scientific Method, Provide identical method of inquiry Focus on scientific reliability Establish a series of steps of investigation Chapter 1 CRC Press: Forensic Science, James and Nordby, 3rd Edition

Ceteris Paribus Laws

“ Other things being equal”

Scientists use the Scientific Method,

Provide identical method of inquiry

Focus on scientific reliability

Establish a series of steps of investigation

Reliable Method of Inquiry: The Common Ground of Theoretical and Forensic Science Reliable methods possess characteristics of: Integrity Competence Defensible Technique Relevant Experience Chapter 1 CRC Press: Forensic Science, James and Nordby, 3rd Edition

Reliable methods possess characteristics of:

Integrity

Competence

Defensible Technique

Relevant Experience

Forensic Experts and their role Scientists explain phenomena by starting with data surrounding an event or inquiry Suggest explanatory connections to pursue and test Distinguish data that are evidence from data that is coincidental Share a fundamental approach in common with other scientists Chapter 1 CRC Press: Forensic Science, James and Nordby, 3rd Edition

Scientists explain phenomena by starting with data surrounding an event or inquiry

Suggest explanatory connections to pursue and test

Distinguish data that are evidence from data that is coincidental

Share a fundamental approach in common with other scientists

Role of the Forensic Expert Expert witnesses can only be declared by a judge Forensic Scientists remain a scientist first and are an expert secondary to that role Give expert opinions within area of expertise Used when facts are unclear in a case or When clarification of procedures is needed or When a jury needs assistance in making an educated decision Chapter 1 CRC Press: Forensic Science, James and Nordby, 3rd Edition

Expert witnesses can only be declared by a judge

Forensic Scientists remain a scientist first and are an expert secondary to that role

Give expert opinions within area of expertise

Used when facts are unclear in a case or

When clarification of procedures is needed or

When a jury needs assistance in making an educated decision

Scientific Method Features implementation of reliable methods Distinguishes evidence from ambiguity Allows ranking of alternative results by a principle basic to that science Allows for certainty considerations based upon ranking of alternative results Disallows hypotheses more extraordinary than facts themselves Chapter 1 CRC Press: Forensic Science, James and Nordby, 3rd Edition

Features implementation of reliable methods

Distinguishes evidence from ambiguity

Allows ranking of alternative results by a principle basic to that science

Allows for certainty considerations based upon ranking of alternative results

Disallows hypotheses more extraordinary than facts themselves

Scientific Method Pursues general impressions to the specific level of detail Pursues testing by breaking hypotheses (alternative explanations) into their smallest logical components, one part at a time Allows tests either to prove or to disprove alternative explanations (hypotheses) Chapter 1 CRC Press: Forensic Science, James and Nordby, 3rd Edition

Pursues general impressions to the specific level of detail

Pursues testing by breaking hypotheses (alternative explanations) into their smallest logical components, one part at a time

Allows tests either to prove or to disprove alternative explanations (hypotheses)

Forensic Scientists Reason from a given set of results (crime scene) To probable explanation (link to perpetrator) And explain these results to justify they are better than other alternative explanations Chapter 1 CRC Press: Forensic Science, James and Nordby, 3rd Edition

Reason from a given set of results (crime scene)

To probable explanation (link to perpetrator)

And explain these results to justify they are better than other alternative explanations

Forensic Scientists Must attach some degree of certainty to their work Should not omit larger issues which could lead to a false opinion Leave out the precision of mathematics and probability theory Must develop an intellect not too sure of what must remain uncertain, not too certain of what must remain sure. Chapter 1 CRC Press: Forensic Science, James and Nordby, 3rd Edition

Must attach some degree of certainty to their work

Should not omit larger issues which could lead to a false opinion

Leave out the precision of mathematics and probability theory

Must develop an intellect not too sure of what must remain uncertain, not too certain of what must remain sure.