- 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
The Constitution does not require the police or prosecution to preserve all potential evidence. The critical distinction is between evidence that is materially relevant and evidence that is potentially useful. Police loss or destruction of potentially useful evidence (i.e., evidence that might prove exculpatory if tested) does not violate due process "unless a criminal defendant can show bad faith on the part of the police."1 At the same time, loss of (or failure to disclose) material exculpatory evidence establishes a due process violation.2
