You are defense counsel in a case with DNA evidence or where the absence of DNA evidence may raise factual or legal issues. DNA evidence, when properly collected and analyzed, and when relevant to an alleged crime, can have extraordinary value in the adjudication of a criminal case. This notebook is designed to help defense attorneys understand: n The biology of DNA. n Proper collection procedures for DNA evidence. n Interpretation of DNA analysis and findings. n When and why an expert is needed. n Development of case theory in a DNA-based prosecution or in a case where there should be DNA evidence. n Legal issues for pretrial and trial in cases with DNA evidence. n Postconviction cases.