Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
COLLECTION OF EVIDENCE BLOOD AND OTHER BODY FLUID STAINS AND REFERENCE SAMPLES FOR CONVENTIONAL TYPING AND DNA ANALYSIS Blood and other body fluid stains may be encountered as physical evidence in a variety of crimes such as homicide, vehicular hit-and-run, and burglary. The identification and typing of blood and other body fluid stains can assist in establishing elements of the crime, identifying or eliminating a suspect, and can be used to corroborate or dispute the statements of principals. I. General Crime Scene - Collect all items at the scene having possible evidentiary value ; i.e., anything which might have originated from the suspect/victim (depending upon nature of scene) or provide information about what occurred. Process the crime scene systematically for evidence: Photos : To record the scene and identify items of evidence. Sketches : To establish spatial relationships. Latent Prints : Best evidence for identification of the suspect(s); should always be considered. Footprints, Tire Tracks, Toolmarks : Impression evidence that may serve to identify suspect(s). Biological Evidence - Biological evidence includes blood, saliva, semen and other body fluid stains. Any of this evidence may be important and should be collected. These stains should be accompanied by control samples from unstained areas near the collected stains. A forensic light source (e.g. Polilight ) may be of assistance in locating these stains. II. Blood and Other Body Fluid Stains Found at Crime Scene - All biological evidence is subject to deterioration. The careful collection and storage of this evidence will help ensure that this evidence is preserved so that useful information can be obtained from its analysis. The pattern of bloodstain evidence may sometimes contain important information. If the bloodstain pattern is determined to be important, it should be documented with appropriate sketches and photographs. Finally, biological evidence can contain infectious organisms (e.g. hepatitis virus) that can be transmitted to any person who contacts it. For these reasons, it is important to take proper safeguards to ensure the safety of all personnel. A. Safeguards while handling biological evidence include : Wear gloves Keep any contaminated surface (e.g. gloved hand) away from face to prevent contact with mucosal membranes (e.g. eyes, nose). After dealing with evidence, properly dispose of gloves and wash hands with germicidal soap
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 09/08/2010 for the course JS 113 at San Jose State University .

Page1 / 3


This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online