U5 Serology - Mrs. Slovacek's Science

U5 Serology - Mrs. Slovacek's Science

U5 SEROLOGY 5.4 Blood Spatter Patterns BLOOD SPATTER PATTERNS Blood spatter patterns are generally classified into three categories: Passive Transfer Projected BLOOD SPATTER PATTERNS: PASSIVE Passive Bloodstains are drops created or formed by the force of gravity acting alone. Types include: Flows Pools

Drip trails Drip patterns Simple drops BLOOD SPATTER PATTERNS: PASSIVE Flows: patterns made by drops or large amounts of blood flowing by the pull of gravity. Remember, the blood will flow towards the ground because of gravity so the direction of the flow can tell us a lot about the position of the body or object Ex: if the body or object was moved, sequence of events, time between the flow and if it was interrupted, etc. Pools: occur when blood collects in a level (not sloped)

and undisturbed place. Blood that pools on an absorbent material (like a mattress or couch) will cause the pool to be much larger than the original pool because of diffusion. The approximate drying time of a pool can be determined through experimentation and can tell investigators an approximate amount of time that has passes since the blood was deposited and when it was found. Skeletonization: when the edges of a stain dry to the surface creating a ring. Usually occurs within 50 seconds and can be used to see if the activity occurred shortly after it was deposited or later. It is important to help classify the source of the original stain.

BLOOD SPATTER PATTERNS: PASSIVE Drip trails: a series of drops that are separate from other patterns, formed by blood dripping off an object or injury. The stains form a kind of line or path, usually made by a suspect after injuring or killing a victim. They can show: Direction of movement of the victim or suspect Lead to a discarded weapon Identification of a suspect through DNA Speed of movement Circular stains, close together indicate slow movement Stains far apart indicate fast movement

Drip patterns: A blood stain pattern that results from blood dripping into blood. Simple drops: made from a stationary position due to the force of gravity. Can show height of the source of blood BLOOD SPATTER PATTERNS: TRANSFER A transfer bloodstain is created when a wet, bloody surface comes in contact with a secondary surface. Types include: Contact

Swipe or smear BLOOD SPATTER PATTERNS: TRANSFER Contact: when an object makes contact with the surface and the object is removed without any movement. Tool impressions, fingerprints, handprints, footprints, footwear prints, fabric prints Can also show direction of movement when the transfers are separate (like footprints) because the patterns will start out dark and then get lighter as you move away from the source. This can also be an indication of speed of movement as well.

Swipe or smear: when a bloody object moves across a surface. The pattern will generally lighten and feather as the pattern moves away from the initial contact point showing the direction of movement. However, feathering is also a function of pressure so you have to be careful when analyzing swipe patterns. BLOOD STAIN PATTERNS: PROJECTED Projected bloodstains are created when an exposed blood source is subjected to an action or force, greater than the force of gravity. (Internally or Externally produced)

Types include: Gunshot Cast-off Arterial spray Expirated Void BLOOD STAIN PATTERNS: PROJECTED Gunshot: high velocity impact so most of the spatter is very fine droplets. Usually causes both forward and back splatter. Forward spatter is from the exit wound Back splatter can tie a suspect or gun to the victim and will depend on the location of the injury, the size of the wound created, and the distance between the muzzle of the weapon and the victim.

Back spatter on a suspect or gun can indicate proximity to the victim at the time the spatter was created BLOOD STAIN PATTERNS: PROJECTED Cast-off: A blood stain pattern created when blood is released or thrown from a moving, blood bearing object. Usually occurs between different strikes of an object and will include a forward and backward motion creating an arc. By counting the pairs-you can indicate the number of strikes You can determine the type of weapon used by the width of the cast off pattern because the size of the drops is directly related to the size of the point that they were propelled from. Small drops = sharp point OR small amount of blood Large drops = large or blunt surface OR large amount of blood Direction of the strike: the pattern will point in the direction of the backward thrust,

which is the opposite of the direction of the blow. Could suggest which hand the blow was delivered with. BLOOD STAIN PATTERNS: PROJECTED Arterial spray: occurs when the victim suffers an injury to a main artery or the heart and the pressure of the continuing pumping blood causes the blood to spurt out of the injured area. Usually shows large spurted stains for each time the heart pumps with uniform shaped and size drops in parallel arrangement. The first strike will leave the biggest and darkest pattern, and they will get smaller and lighter as the blood is drained. Vertical arcs or waves in the line show a fluctuating blood pressure

Can include radial spikes, satellite spatter, or flow patterns because of the large amount of blood. Tends to be a brighter red color. BLOOD STAIN PATTERNS: PROJECTED Expirated: a pattern created by blood that is expelled from the mouth or nose from an internal injury. If the blood is under great pressure, it will create fine, high velocity spatter. If the blood in under low pressure, it will create a cluster with irregular edges. Often includes the presence of air bubbles and can be lighter in color due to dilution from saliva.

Void: an object blocks the deposition of blood spatter on a surface or object. The spatter is deposited onto the object or person instead. It can give a clue about the size and shape of a missing object or person. Can help to show the body position of the victim or assailant at the time of the incident.

Recently Viewed Presentations

  • Belvedere College SJ CAO Information Evening Tuesday13th November

    Belvedere College SJ CAO Information Evening Tuesday13th November

    www.ucas.com. Open days - College visits - Currently in full swing. Current students / graduates. What is the CAO? What is the CAO? Central Applications Office. ... We are going to trace the progress of the applicant marked in red....
  • Voting System Technologies - University Of Maryland

    Voting System Technologies - University Of Maryland

    (a) shows the main visualization of multiple EHRs. (b) is a temporal summary, showing the distribution of the three event types Admit, Exit, and ICU over time. (c) is the control panel for Lifelines2. Each of the 318 patients is...
  • A. Mangroves - University of Arizona

    A. Mangroves - University of Arizona

    Dwarf - isolated, low productivity, low FW, low nutrients E. Understory - lacking due to variety of stressors F. Salinity G. Zonation PowerPoint Presentation PowerPoint Presentation PowerPoint Presentation H. Adaptations Crabs - mangrove maintenance J. Hurricanes PowerPoint Presentation Hurricanes Continued...
  • Documentation Or if it wasnt written down, it

    Documentation Or if it wasnt written down, it

    Eg: need for restrictive practice, health support assessment, mandatory notification, risk assessment, information sharing decisions. If you don't keep notes for example, how do you prove the needs of your customer have changed and get their needs met?
  • Business Letter - S.M.Joshi College

    Business Letter - S.M.Joshi College

    Jon Hamm Please find out more about Jon Hamm through personal research. What can you say to convince him to be our class Valentine? Remember he was hand-selected by your very critical judgy teacher because she thinks he would be...
  • ADD STEAM TO YOUR CURRICULUM, AN OVERVIEW OF

    ADD STEAM TO YOUR CURRICULUM, AN OVERVIEW OF

    Give STEAM acronym. Why to admins need time to collaborate? They need to know the goal to help create the community partnerships. ... Build a craft that would hold all supplies necessary to make the journey. A place to sleep....
  • Portico Archive: Helping libraries make a secure transition ...

    Portico Archive: Helping libraries make a secure transition ...

    The time to act is now. Eileen Fenton [email protected] www.portico.org E-Journal Archiving Metes and Bounds: A Survey of the Landscape Select recommendations to E-Journal Archiving Programs Present public evidence of the minimal level of services necessary for a well-managed collection.
  • The Enlightenment

    The Enlightenment

    Rousseau - Champion of Freedom. Individual freedom. Very different from other philosophes. Civilization corrupted people's natural goodness. Only good government was one that was freely formed by the people and guided by the ""general will" of society. Which is what?...