Evidence Packaging, Forensic science
Evidence Packaging, Forensic science
Popular in Course
verified elite notetaker
Popular in Department
This 12 page Class Notes was uploaded by Carls Ndung'u on Thursday November 5, 2015. The Class Notes belongs to a course at a university taught by a professor in Fall. Since its upload, it has received 182 views.
Reviews for Evidence Packaging, Forensic science
Report this Material
What is Karma?
Karma is the currency of StudySoup.
You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!
Date Created: 11/05/15
Evidence Packaging: Goals of Evidence Packaging 1)Protects personnel from possible hazards associated with evidence: Accidental firearm discharge Biohazards Sharp objects Health hazards associated with exposure to mold •Wet plant material 2)Protects evidence against: Loss Contamination Cross-transfer o Suspect to victim o Victim to suspect o Scene to scene o Item to item Deterioration 3)Correctly identifies evidence with respect to: a.Evidence description: What is it? b.Evidence source i. Origin – where was evidence when it was collected ii. Custodial Agency c. Chain of custody d.Provides a unique identifier so it cannot be confused with any other evidence item i. Laboratory case and item number 4)Can indicate o What processing is needed o For example: “Fingerprint processing required” o Health hazards (e.g. sharp knife) o Required or preferred storage conditions “Store at room temperature” “Store frozen Elements of packaging evidence i) Prepare packaging Certain types of evidence may need to be dried before it can be packaged: o Wet biological samples. If packaged wet, the evidence may “leak” through to the exterior of the container o Fresh plant material ii) Type of packaging Plastic: What type of plastic? o Envelope o Bag Paper Envelopes Bag Boxes Sometimes Paper Containers are Optimal: Biological Samples o Allows a sample that is not completely dry to finish drying and May prevent the deterioration of a biological sample if it is not completely dry when packaged o What Happens When Biological Evidence is Wet? Evidence “leaks” through to the exterior of the container, resulting in: Sample deterioration Sample loss Contamination issues o o Sometimes Plastic Containers areOptimal: Controlled Substances. prevent exposure to potent drugs. iii) Optimal packaging a.Size of container is important i. Too small and the packaging is likely to fail over time ii. • Too big and evidence can be dispersed throughout container and difficult to recover (e.g. powder, trace evidence) b.Does evidence require internal packaging? Sealing Evidence Sealing evidence properly is a requirement of most crime labs o Issues: Type of seal Need for identifying mark Where seal(s) is to be placed Ways evidence can be sealed o Heat seal o Tape seal o Lock seal All seals must be initialed to document the person sealing the evidence and dated to indicate when the evidence was sealed o Seal should completely seal envelope flap o Seal should completely seal bag flap o Staples are not an appropriate evidence “seal” Biological Evidence Insure the sample is dry o Do not dry in a heated air stream Use paper containers Immobilize evidence when necessary o sharps”: knifes, broken glass o when stain could be dislodged Recommendations for Collection of Biological Evidence Collect and package stains separately—do not allow separate stains to come into contact with one another o Sheets of paper can be used to minimize contact of stains on a bloodstained garment o Consider packaging all biological samples separately A bloodstain swab and its control can be separately packed into two coin envelopes and then both envelopes can be placed into the same larger envelope o To minimize the chance of cross transfer of adhering evidence; different clothing items should NOT be packaged in the same container Attempt to ensure that anything that contacts biological samples during collection is free of anything that might contain human DNA o Work on clean surfaces o Wear gloves and change when necessary Packaging a Wet Bloodstain on a Swab o After samples are dried, package the bloodstain sample and the control into separate coin envelopes o Do not use any packaging device that limits air exchange Biological samples will deteriorate if it takes too long for them to dry Once the sample is dried it can be safely placed into a paper envelope and sealed Packaging Bloody Clothing Attempt to allow bloodstains to dry as much as possible Place clothing onto a piece of clean paper o Place paper between stained areas so as to prevent stain transfer o Seal and date paper package with bloody shirt Insert paperpackage into larger paper bag Packaging Trace Evidence Trace evidence is small evidence and can be easily lost o Examples of trace evidence: Hairs Glass fragments Paint flakes Fibers o If it is necessary to remove and package trace evidence, its nature and location must be documented before the evidence is altered Items must be visually examined and trace evidence identified o Trace evidence can be removed with tweezers and placed into appropriate packaging o Trace evidence can also be removed with tape lifts Packaging must be appropriately sized & designed so that this small evidence cannot fall out of the container Glass Fragments are small and can be lost from poorly sealed envelopes o Glass fragments should to be packaged into a bindle before being placed into envelope o The bindle is then sealed before it is inserted into an envelope o Bindles can also be used to package paint fragments F irearms Evidence Packaging Firearms Evidence Record all necessary information about condition of firearm: Position of hammer, safety, & other controls Number and location of fired and unfired cartridges Presence of powder residue on revolver cylinder face Blood or trace evidence visible on gun exterior Firearms can be handled by any surface which does not take fingerprints NEVER PACKAGE A LOADED WEAPON o Remove the magazine & make sure chamber is empty o Do NOT insert anything into the barrel EXTREMELY UNSAFE! Could alter the firearm Could remove blood or trace evidence o Once the firearm has been rendered safe, it can be placed into a cardboard box and Immobilized with a plastic tie Make sure the tie goes BEHIND the trigger o Use packaging that will permit fingerprint, blood and trace evidence to be recovered o Label appropriately and seal o Write “Unloaded” notification on outside of container Fired bullets need to be carefully handled to protect critical markings on the bullet surface and any adhering trace evidence o Do NOT mark bullet o Bullets requires internal packaging. Paper bindles or soft tissue can be used o No need to remove cartridges from the magazine at scene Drug Evidence Drug Evidence Packaging needs to accommodate: Health hazards associated with certain drug items o Syringes o Evidence carried in body cavities Variable characteristics of drug evidence: o Different drugs have different possible health hazards to personnel handling exhibits Some drugs are very potent in small amounts Liquid samples Sharps Multiple forms o Powders, sticky tar, residues, plant material Appropriate Packaging necessary Safely contain drug evidence & protect personnel against unnecessary exposure Need to be heat sealed Airtight o Not good for fresh plant material Seals should not be placed too close to evidence- may make it difficult for the analyst to reseal evidence after analysis should be impervious to chemical solvents Size- right size is necessary - small amount of powder in big container- may be difficult to recover. Electrostatic charge causes it to disperse and cling to plastic surfaces Fresh or wet plant material- use paper envelops or bags- they allow plant to dry and prevent growth of bacteria/mould(Fungal growth) o Plastic containers can be used if plant material is completely dry Packaging Best Practices Summary Agencies should encourage the following best practices in biological evidence packaging. Containers Use paper bags, manila envelopes, cardboard boxes, and similar porous materials for all biological evidence. (See page 10 for specific guidance on wet items.) Use butcher or art paper for wrapping evidence, for padding in the evidence container, and/or as a general drop cloth to collect trace evidence. Package evidence and seal the container to protect it from loss, cross-transfer, contamination, and/or deleterious change. For security purposes, seal the package in such a manner that opening it causes obvious damage or alteration to the container or its seal. Item Packaging Package each item separately; avoid comingling items to prevent cross-contamination. Use a biohazard label to indicate that a potential biohazard is present. Plastic bags are not preferred for storage because of the possibility of bacterial growth or mold. If drying wet evidence is not possible, place the evidence in an impermeable, nonporous container and place the container in a refrigerator that maintains a temperature of 2 °C – 8 °C (approximately 35 °F to 46 °F) and that is located away from direct sunlight until the evidence can be air dried or until it can be submitted to the laboratory. Seal each package with evidence tape or other seals, such as heat seals and gum seals; if possible, do not use staples. Mark across the seal with the sealer’s identification or initials and the date. Unload, make safe, and place all firearms submitted into evidence for biological testing into a new cardboard gun box. As the submitting individual, seal the box and indicate on the exterior of the box that the weapon was unloaded, made safe, and may contain biological material. Label items according to agency policy and procedures. At a minimum, mark each package with a unique identifier, the identification of the person who collected it, and the date of collection. The unique identifier should correspond to the item description noted on the property/evidence report (e.g., evidence tag, property sheet, property receipt, or property invoice). More information on evidence labeling can be found on pages 29 – 30. Maintain the integrity of the item through the package documentation, including all markings, seals, tags, and labels used by all of the involved agencies. Preserve and document all packaging and labels received by
Are you sure you want to buy this material for
You're already Subscribed!
Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'