Collection and Preservation of Physical Evidence

Despite signicant advances in the ability to analyze blood and other forms of biological evidence, if the sample is not properly collected and preserved, no level of sophistication will correct for mishandling a biological sample (Marjanovic and Primorac, 2013). In fact, most legal challenges regarding physical evidence such as blood evidence focus on the recognition, collection, and preservation matters rather than the scientic methodologies that were used to analyze the sample (Fisher and Fisher, 2012). e Scientic Working Group9.1 Introduction 253 9.1.1 Sample Collection from Victim or Suspect 2549.1.1.1 Known Oral Swab Standards 254 9.1.1.2 Liquid Urine and/or Fecal Material 254 9.1.1.3 Vaginal Materials 255 9.1.1.4 Nasal Mucous 255 9.1.1.5 Bite Mark Evidence 255 9.1.1.6 Skin Tissue 255 9.1.1.7 Clothing or Personal Items 2569.2 Recognition and Identication of Blood Evidence 256 9.2.1 Presumptive Blood Tests 256 9.2.2 Conrmatory Blood Tests 2589.3 Collection Methods for Blood 260 9.3.1 Dried Blood Stains 260 9.3.2 Liquid Blood Samples 261 9.3.3 Seminal Stains 262 9.3.4 Stains from Other Physiological Fluids 2639.4 Blood Stain Pattern Analysis 264 9.5 Crime Scene Reconstruction 265 9.6 Case Examples 2669.6.1 Concetta “Penney” Serra Homicide Case 266 9.6.2 Identical Twins, New Orleans, LA 269 9.6.3 Murder in a Bathroom, Middletown, CT 271 9.6.4 Brown’s Chicken Murders 273References 276for DNA Analysis and Methods (SWGDAM) has suggested several best practices for the collection of blood found at crime scenes and is an excellent resource.