Forensics
Hypotheses tested empirically
Error measured systematically
Conclusions stated with uncertainty
Claims limited to what data support
What is Scientific validation model?
the method accurately measures, classify, or discriminate what it claims to measure
What is Validity?
The 3 types of forensics problem occurred by a person
Good-faith examiner error
Contextual bias
Intentional misconduct
Developed largely within law enforcement
Practice-based expertise
Courts admitted techniques over time
Strong individualization claims became routine
What is traditional forensic model?
examiners using the method reach consistent results under similar conditions
What is Reliability?
The 4 Type of Forensics problem occurred in the laboratory
Weak quality control
Poor supervision
Inadequate documentation
Lack of independence
Often grounded in biology and population genetics
Can often provide quantitative probability estimates
Has standardized analytical practices
Still requires proper collection, interpretation, and
communication
What is DNA evidence?
the testimony accurately convey what the method and
evidence permit us to conclude
What is communication Validity?
The 3 Type of Forensics problem occurred in the courtroom
Weak method validation
Unsupported individualization
Testimony that overstates what the method can show
Often involves human visual judgment
Similarity does not automatically establish source
Error depends on task difficulty, examiner, method,
and procedure
Testimony must be limited to what studies support
What is pattern comparison evidence?
Has empirical research shown the method can produce accurate results under appropriate conditions
What is Foundational Validity?
The task/information that is irrelevant to the examiner
The suspect confessed
Eyewitnesses identified the suspect
The suspect has a prior record
Police “know he did it”
Prosecutors urgently
Major debunked and discredited forensics
What is:
Bite-Mark Analysis
Microscopic Hair Comparison
Shaken Baby Syndrome (SBS)
Arson Investigation (Junk Science)
Comparative Bullet Lead Analysis
Blinding, Information management, and Independent verification are examples of
What is reduce bias?
a wrongful-conviction crisis when the system lacks auditing, supervision, documentation, and disclosure mechanisms.
What is Individual misconduct?