- 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 12 :: Victim Issues
Topic 2 :: DNA Evidence Testing
Why Is There No DNA Evidence or Results from DNA Analysis?
DNA is transferred to an item of evidence through the physical transfer of biological material such as blood or saliva. While biological material that is properly collected, packaged, and stored can successfully be tested for DNA many years after the commission of a crime, sometimes environmental or other factors can degrade DNA, which can negatively affect DNA analysis results.
For more information on factors affecting DNA analysis, see Module 3, Practical Issues Specific to DNA Evidence.
