Forensics Chapter 10 Blood Spatter Flashcards
55 Questions
100 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

The _____, _____, and ______ of bloodstains may be useful for ____ and _____ the events that produced the bleeding.

location, distribution, appearance; interpreting, reconstructing

What is very important in the interpretation of bloodstain patterns?

surface texture

The harder and less porous the surface is, the ____ spatter.

less

The _____ of travel of blood striking an object may be discerned by the stain's shape.

<p>direction</p> Signup and view all the answers

The _____ end of a bloodstain always faces its direction of travel.

<p>pointed</p> Signup and view all the answers

How can the angle of impact be measured on a flat surface?

<p>by the degree of circular distortion of the stain</p> Signup and view all the answers

A drop of blood striking a surface at 90 degrees produces a nearly _____ stain.

<p>circular</p> Signup and view all the answers

As the angle of the stain decreases, the stain _____ .

<p>elongates</p> Signup and view all the answers

The _______ of blood drops increases as height increases.

<p>diameter</p> Signup and view all the answers

What pattern occurs when an object impacts a source of blood?

<p>impact spatter</p> Signup and view all the answers

What type of spatter travels away from the source of blood and in the same direction as the force that caused it?

<p>forward spatter</p> Signup and view all the answers

What is produced when blood is projected backward toward the source of the force?

<p>back spatter</p> Signup and view all the answers

What does an entrance wound do in terms of blood deposition?

<p>can deposit blood on the object or the person creating the impact</p> Signup and view all the answers

As the force of the impact _____, the velocity of the blood drops produced increases.

<p>increases</p> Signup and view all the answers

As both force & velocity of the impact increase, the diameter of the blood drops _______.

<p>decrease</p> Signup and view all the answers

What type of spatter produces large, separate or compounded drops with diameters 3 mm or greater?

<p>low velocity spatter</p> Signup and view all the answers

What type of spatter produces small drops with diameters from 1-3 mm?

<p>medium velocity spatter</p> Signup and view all the answers

What type of spatter produces very fine drops with diameters 1 mm or less?

<p>high velocity spatter</p> Signup and view all the answers

What type of spatter is often produced by gunshot exit wounds or explosions?

<p>high velocity spatter</p> Signup and view all the answers

What defines the area on a two-dimensional plane from which blood drops meet?

<p>area of convergence</p> Signup and view all the answers

How can the area of convergence be established?

<p>by drawing straight lines through the long axis of several individual bloodstains to see where they intersect</p> Signup and view all the answers

What indicates the area in a three-dimensional space from which blood was projected?

<p>area of origin</p> Signup and view all the answers

The area of origin shows the _____ of the victim or suspect in space when the stain-producing event took place.

<p>position</p> Signup and view all the answers

The area of origin gives general _____ between blood source to blood-stained surface.

<p>distance</p> Signup and view all the answers

As distance from the area of origin surface _____, the distribution and distance between drops increases.

<p>increases</p> Signup and view all the answers

What type of spatter typically produces both forward and back spatter?

<p>gunshot spatter</p> Signup and view all the answers

In gunshot spatter, if the bullet does not exit the body only ____ _____ is produced.

<p>back spatter</p> Signup and view all the answers

Finding ____ _____ ____ containing the victim's blood on a suspect can help investigators place the suspect in the vicinity of the gunshot.

<p>high velocity spatter</p> Signup and view all the answers

What is the drawback effect in forensics?

<p>when the victim of a shooting's blood back spatters onto the gun or shooter</p> Signup and view all the answers

What occurs when a blood-covered object flings blood in an arc onto a nearby surface?

<p>cast off spatter</p> Signup and view all the answers

When does cast off spatter commonly occur?

<p>when a person pulls a bloody fist or weapon back between delivering blows to a victim</p> Signup and view all the answers

Blood from a small or sharp object will produce ____ drops.

<p>small</p> Signup and view all the answers

Blood from a blunt or large object will produce ____ or _____ drops.

<p>larger, wider</p> Signup and view all the answers

What can determine if the blow was going from left to right or in the reverse?

<p>cast off spatter</p> Signup and view all the answers

Cast off spatter shows the ____ number of blows delivered to a victim; each blow produces a _____ _____.

<p>minimum; separate arc</p> Signup and view all the answers

What type of spatter is produced when a victim suffers an injury to a main artery or the heart?

<p>arterial spray spatter</p> Signup and view all the answers

What causes blood to spurt out of injured areas in arterial spray spatter?

<p>the pressure of the continuing pumping of blood</p> Signup and view all the answers

What pattern is expelled from the mouth or nose from an internal injury?

<p>expirated blood patterns</p> Signup and view all the answers

What do expirated blood patterns provide clues about?

<p>the type of injuries that occurred or the events that took place during a crime</p> Signup and view all the answers

What is created when an object blocks the deposition of blood spatter onto a target surface or object?

<p>void patterns</p> Signup and view all the answers

What can void patterns provide clues about?

<p>the type of missing object or the size of the person</p> Signup and view all the answers

What produces this kind of stain when an object with blood on it touches one that does not have blood on it?

<p>contact/transfer patterns</p> Signup and view all the answers

What do contact/transfer patterns include?

<p>fingerprints, handprints, footprints, or toolprints</p> Signup and view all the answers

What are patterns made by drops of blood flowing by the pull of gravity?

<p>flow patterns</p> Signup and view all the answers

What may flow patterns come from?

<p>an actively bleeding wound or blood deposited on a surface from an arterial spurt</p> Signup and view all the answers

What do flow patterns demonstrate?

<p>movements of objects or bodies while the flow was still in progress</p> Signup and view all the answers

What occurs when blood collects in a level and undisturbed place?

<p>pools</p> Signup and view all the answers

The approximate drying time of a pool of blood is related to the ______ _____ of the scene.

<p>environmental conditions</p> Signup and view all the answers

What is a series of drops that are separate from other patterns, formed by blood dripping off an object or injury called?

<p>drip trail patterns</p> Signup and view all the answers

What may drip trail patterns form?

<p>a line or path made by a suspect and can indicate type of movement</p> Signup and view all the answers

The tails of drops will point in the _____ the person was moving.

<p>direction</p> Signup and view all the answers

Investigators should note, study, and photograph each ____ and ____ of blood at a crime scene.

<p>pattern, drop</p> Signup and view all the answers

What type of documentation should show the whole pattern and relationships between stains?

<p>medium range documentation</p> Signup and view all the answers

What type of documentation should show the dimensions of individual stains with a ruler next to the stain?

<p>close up documentation</p> Signup and view all the answers

The _____ ____ ____ determination should be noted whenever possible and all measurements and calculations of angles should be recorded in the crime scene notes.

<p>area of origin</p> Signup and view all the answers

Study Notes

Blood Spatter Analysis

  • Bloodstains' location, distribution, and appearance are crucial for interpreting and reconstructing events related to bleeding.
  • Surface texture significantly influences bloodstain pattern analysis.

Bloodstain Characteristics

  • Hard, less porous surfaces produce less spatter.
  • The direction of blood travel can be determined by the shape of the stain.
  • The pointed end of a bloodstain indicates its direction of travel.

Impact and Angle

  • The angle of impact can be assessed by the circular distortion of a stain on a flat surface.
  • A blood droplet striking a surface at 90 degrees results in a nearly circular stain.
  • As the angle decreases, the bloodstain appears elongated.
  • The diameter of blood droplets increases with height.

Types of Spatter

  • Impact spatter arises when an object contacts a blood source, disseminating blood outward.
  • Forward spatter moves away from the blood source in the direction of the impact force.
  • Back spatter projects toward the source of the force, typically seen in entrance wounds.

Velocity Classification

  • Low velocity spatter: large, separate drops (3mm+), caused by slow-moving forces (<5 ft/sec).
  • Medium velocity spatter: smaller drops (1-3mm), associated with blunt force trauma (5-25 ft/sec).
  • High velocity spatter: very fine droplets (<1mm), produced by rapidly traveling forces (≥100 ft/sec), often linked to gunshot wounds.

Convergence and Origin

  • The area of convergence is identified by drawing lines through the long axes of bloodstains to find intersections.
  • The area of origin signifies the spatial origin of where blood was projected, indicating the victim's or suspect's position during the event.
  • Greater distance from the area of origin typically increases the distribution and spacing of blood drops.

Gunshot Spatter Dynamics

  • Gunshot spatter usually creates both forward and back spatter.
  • If a bullet does not exit, only back spatter is produced.
  • Finding high velocity spatter containing victim’s blood on a suspect helps establish their proximity to the crime.

Other Spatter Patterns

  • Drawback effect occurs when a shooter's blood splatters back onto them, indicating their presence at the scene.
  • Cast off spatter results when a bloodied object swings, flinging blood onto surfaces.
  • The characteristics of the object (small/sharp vs. blunt/larger) affect the size and spread of drops.

Spatter Evidence

  • Arterial spray spatter occurs from injuries to major arteries, with blood spurting under pressure.
  • Expirated blood patterns emerge from the mouth or nose, providing injury-related clues.
  • Void patterns arise when an object blocks blood deposition, aiding in reconstructing crime scene elements.
  • Contact/transfer patterns result from bloodied objects touching non-bloodied surfaces, including prints.
  • Flow patterns indicate the movement of blood influenced by gravity, often originating from spurt injuries.

Documentation Practices

  • Investigators should observe, study, and photograph every pattern and drop of blood.
  • Medium range documentation should capture entire patterns and relational placement of stains.
  • Close-up documentation must show individual stain dimensions with rulers for measurement accuracy.
  • Area of origin measurements and angle calculations should be meticulously recorded in crime scene notes.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Quiz Team

Description

Test your knowledge of blood spatter analysis with this collection of flashcards from Forensics Chapter 10. Learn key terms and concepts related to the interpretation and reconstruction of bloodstain patterns. Perfect for anyone studying forensic science and its applications in crime scene investigations.

More Like This

Crime Scene Investigation Quiz
12 questions

Crime Scene Investigation Quiz

RefreshedHyperbole avatar
RefreshedHyperbole
Forensic Science: Blood Typing and Spatter Analysis
22 questions

Forensic Science: Blood Typing and Spatter Analysis

AttentiveRococo avatar
AttentiveRococo
Use Quizgecko on...
Browser
Open
Browser
Browser