- 01 Introduction
- 02 Biology of DNA
- 03 Practical Issues Specific to DNA Evidence
- 04 Introduction to the Forensic DNA Laboratory
- 05 Assuring Quality in DNA Testing
- 06 Understanding a Forensic DNA Lab Report
- 07 Statistics and Population Genetics
- 08 Mitochondrial DNA & Y-STR Analysis
- 09 Forensic DNA Databases
- 10 Collection of DNA Evidence from Suspects and Arrestees
- 11 Pretrial DNA Evidence Issues
- 12 Victim Issues
- 13 Trial Presentation
- 14 Postconviction DNA Cases
- 15 Emerging Trends
Principles of Forensic DNA
for Officers of the Court
for Officers of the Court
Module 11 :: Pretrial Issues
Topic 1 :: Discovery Issues Related to DNA Evidence
Basic Discovery—The Duty to Preserve (cont.)
The specific failure to preserve biological crime scene samples for DNA testing has been held not to violate due process principles in the absence of bad faith. The police must know before destruction that the evidence would in fact have exculpated the suspect/defendant.
[R]espondent has not shown that the police knew the semen samples would have exculpated him when they failed to perform certain tests or to refrigerate the boy's clothing; this evidence was simply an avenue of investigation that might have led in any number of directions. The presence or absence of bad faith by the police for purposes of the Due Process Clause must necessarily turn on the police's knowledge of the exculpatory value of the evidence at the time it was lost or destroyed3
