Customers may request that a case receive “Rush” status. The request must be in writing and contain minimally: case number, reason for request, and preferred date of receipt. Coverage Area The STPSO Crime Lab routinely provides services to the Louisiana 22nd Judicial District which includes St. Tammany and Washington Parishes. Other agencies may request services from the STPSO Crime Lab; however, service provision is at the discretion of the STPSO Crime Lab. General Safety Information Physical evidence being submitted for forensic testing can pose significant safety hazards. It may not always be possible to determine if evidence poses a biological or chemical hazard, so it is imperative to follow universal safety precautions when handling all evidence. According to the concept of Universal Safety Precautions, all human blood and certain body fluids are treated as if known to be infectious for human immunodeficiency virus (HIV), hepatitis B virus (HBV), and other blood borne pathogens. All body fluids should be handled with caution. Evidence that is a potential biohazard should be plainly marked with biohazard stickers. Suspected hazardous chemicals and sharps must also be plainly marked. General Case and Evidence Acceptance Policies The STPSO Crime Lab will receive and examine evidence submitted by the criminal justice community investigating a potential criminal action. The following types of cases and/or evidence not generally accepted: Evidence from private individuals or businesses. Non-criminal, not capable of being charged criminally, or not probative in a cause of death determination. Requests which limit the scope of the agency’s investigation. “Compromised” or affected evidence that renders scientific examinations invalid. Previously examined evidence. The Crime Lab Director or designee may allow exceptions to this policy on a case-by- case basis. Packaging Proper packaging, identification, and sealing of evidence is imperative to its preservation and integrity. Keep in mind to change gloves between handling different items of evidence. Evidence should be packaged: In the manner in which it was found. Items found in contact with each other, should be
Distance Determination Gunshot residue may not be visible on the evidentiary item and should be submitted to the lab to determine suitability. Shooting Reconstruction Requests for service are initiated through approval by the Crime Lab Director or designee. In order to perform this examination, the analyst must have access to the original crime scene. Shooting reconstruction requires the direct observation of ejected cartridge casings, projectile impact, and exact measurements of scene conditions etc. and must be performed before firearms related evidence is collected from scene. Reconstructions will not be performed from crime scene photos. Evidence for Tool mark Examination Submit photograph of the tool mark showing its location in the scene. Make note of how the tool may have been used in order to make the mark. Remove the tool mark from the scene, mark and package it properly. If the tool mark cannot be removed from the scene, make a cast of the tool mark using a silicone based casting material. Collection and Packaging: Firearms MUST be unloaded; very rare exceptions exist (e.g. rusted or damaged firearms) The firearm should be secured with a zip-tie through the action. The weapon conditions should be noted: cocked/uncocked, safety on/off, sequence of cartridges in the cylinder, etc). For revolvers, the outside of the chamber under the firing pin should be marked as the “1” position before opening and the position/condition of cartridges noted. Metal Evidence Recovered from Water/Liquid Submit immediately in the water in which it was located. Ensure that the item of evidence is completely submerged, slowing the oxidation process and slowing evidence destruction. Cartridges and Bullets Package spent cartridge cases and bullets so that the tool marks are protected. For example, package each item separately before placing the items in the submission envelope. Tools Such that the area which had to have been used to make the tool mark is protected from further contact with other objects. For example, the handle of the screwdriver need not be protected but the bladed end must be