What is the average salary for a bloodstain pattern analysis?
What is the average salary for a bloodstain pattern analysis? The U.S. Bureau of Labor Statistics (BLS) reports that forensic science technicians made an average of $61,220 in 2017 and earned a midpoint, or median salary of $57,850. A starting blood spatter analyst salary is around $42,000 a year.
What does a bloodstain pattern analyst do?
What does a bloodstain pattern analyst do? Bloodstain pattern analysts, also known as blood spatter experts, collect and analyze physical evidence—specifically, blood. They are specialists in forensic science and crime scene investigation and examine the location and shape of blood drops, stains, puddles, and pools.
What does a blood splatter analyst do?
Blood spatter analysts are forensic science technicians specialized in collecting and analyzing blood evidence. They examine the location and shape of bloodstains in order to help detectives and investigators solve cases. Blood spatter analysts take photographs, collect, catalog and preserve evidence, write reports and testify in court.
How to become a blood spatter analyst?
To become a blood spatter analyst, you can expect to follow steps similar to the following:
- Acquire the education and experience needed for the blood spatter analyst position you are targeting.
- Apply for a position as a blood spatter analyst.
- Pass a background check.
- Take and pass a drug test.
- Be interviewed for the position.
- Get hired as a blood spatter analyst.
- Receive job training once hired.
What does bloodstain pattern analysis example?
Bloodstain pattern analysis seeks to define the facts surrounding an investigation by the use of the physical nature of bloodstains. Bloodstain pattern analysis is the use of the size, shape, and distribution patterns of the bloodstains found at a crime scene to reconstruct the bloodshed event(s).
What 4 things can blood spatter analysis tell us?
Blood Spatter Analysis Analysis of a spatter pattern can aid in determining the: • direction blood traveled. angle of impact. point of origin of the blood. velocity of the blood.
What does the blood spatter pattern indicate?
Spatter bloodstain patterns The amount of energy involved in the force will determine the size of the blood spatters. More specifically, smaller patterns indicate that a greater amount of force was used. Typically, impacted blood spatter can be classified as medium- or high-force impact spatters.
What can an investigator learn from the analysis of a blood spatter?
Based on the varying sizes and shapes of the blood drops, investigators can often tell what type of weapon caused the spatter, determine the general area where the attack occurred, and track the positions of the victim.
Is blood spatter analysis accurate?
Our results show that conclusions were often erroneous and often contradicted other analysts. On samples with known causes, 11.2% of responses were erroneous. The results show limited reproducibility of conclusions: 7.8% of responses contradicted other analysts.
When was blood analysis first used in forensics?
Modern toxicology began in 1813 when Mathieu Orfila developed tests for the presence of blood, and used a microscope to investigate blood and bodily fluids. In 1900 human blood groups were identified, and in 1915 a method for determining blood types was discovered - and was used immediately in criminal investigations.
What can blood pattern analysis tell us about a crime?
This analysis can provide information in a number of ways including the location of an assault: the type of “weapon” used, the number of blows involved in an attack, the positions of the victim and the assailant at the scene, the likelihood of blood being deposited on the offender and may also provide information to ...
Why is it important to analyze bloodstain patterns in forensics?
Bloodstain pattern analysis provides important forensic information about the crime under investigation; it tells what happened. Bloodstain patterns occur in several distinct categories, each revealing a piece of the crime scene puzzle.
What factors affect blood spatter patterns?
Several factors influence the appearance of satellite spatter, including the blood drop volume, freshness of blood, surface texture, and distance of the vertical target from the impact site.
What must Investigators do before analyzing blood stains?
Analysts or investigators will typically soak up pooled blood, or swab small samples of dried blood in order to determine if it is human blood and then develop a DNA profile. This becomes critical when there are multiple victims.
How do you identify blood stains?
Luminol is often combined with hydrogen peroxide to react with the heme groups in blood, producing a bright blue glow, known as chemiluminescence. This glow allows crime scene technicians to detect blood that has dried on surfaces or to detect blood that someone tried to clean from a surface.
What methods are used to detect blood?
Further tests at the crime lab can determine if it is human blood or not. The Kastle-Meyer tests uses phenolphthalein and hydrogen peroxide, while HemaStix is a paper strip coated with TMB. This chemical is used to locate traces of blood, even if it has been cleaned or removed.
What are the 4 types of passive bloodstains?
Passive. a. formed from the force of gravity acting alone. b. subdivided (drops, drip patterns, pools, clots) c. oozing or gushes from the body, dripping finger or arm, drops from a knife.Transfer. a. wet bloody surface comes in contact with a secondary surface. b. wipe, smudge, swipe or smear. c. ... Projected blood spatter.
What are 2 things a forensic ballistics expert would help detectives determine?
Ballistics experts can identify a weapon by the markings left behind on a bullet or bullet casing after firing. They can determine where the gun was fired from by analyzing the angle of entry, the caliber of bullet, and the depth of the wound.
How is blood evidence detected at a crime scene?
The search for the presence of blood at a crime scene is normally done by close visual examination. The possibility exists, however, that blood may be present in amounts too little to see with the unaided eye, or that the blood at the scene had been “cleaned up” prior to arrival of the crime scene team.
Why is it important to know how blood patterns differ on different surfaces?
It is important to know how blood patterns differ on different surfaces that way you can tell how they behave. Blood dropping onto smooth surfaces tend to splatter and go their own ways where as on a rough surface they pull together like a puddle.
What is the role of blood stain analysis?
The general role of the Bloodstain Pattern Analyst in a criminal investigation is to assist in the reconstruction of those events of an alleged incident that could have created the stains and stain patterns present at a crime scene, on items of physical evidence recovered from that scene and on items of clothing that were present at the crime scene. In some cases, it may be necessary to conduct a bloodstain pattern interpretation using photographs. The usefulness of individual bloodstains and bloodstain patterns lies in their retention of information descriptive of the possible events that could have produced them. The sizes of the individual stains composing a pattern, the shapes of these stains and their distribution relative to one another can be utilized for the purposes of determining how a particular stain or pattern may have been produced. Bloodstain pattern analysis evaluations are conducted to determine what action (s) or sequence of actions could have created the bloodstains and/or patterns observed. Information that may be gained with bloodstain pattern analysis include, for example, the position of the individual when the blood was deposited (sitting, standing, etc.), the relative position of individuals at the time of bloodshed, the possible type of weapon used as well as possible mechanisms that could have produced the blood staining on a surface.#N#The recognition and characterization of different bloodstain pattern types requires considerable training. A few types of patterns follow.
What is the purpose of the size of the individual stains composing a pattern?
The sizes of the individual stains composing a pattern, the shapes of these stains and their distribution relative to one another can be utilized for the purposes of determining how a particular stain or pattern may have been produced.
How was the pattern above created?
The pattern above was created by an object striking a blood source below and in front of the vertical surface pictured. This is an Impact Pattern.
What is blood stain pattern analysis?
Bloodstain pattern analysis (BPA) involves the study and analysis of bloodstains. In forensic work, bloodstain pattern analysis can help investigators find out more about certain aspects of previous events that took place at a place that is known or suspected of being linked to a crime in a significant way.
What is the book Bloodstain?
It mentions bloodstain analysis, but only briefly. Examples of facts pointed out in the book are that bloodsta ins tend to fall in certain patterns based on the motion of an attacker and the victim, and that blood dries at a relatively predictable rate.
What is the IABPA?
IABPA was founded by a group of blood stain analysts who wished to further the then emerging field of bloodstain pattern analysis. It was in the early 1980s that forensic BPA started to grow and become a fairly regular occurrence in violent crime investigations in the United States. One of the main objects f the IABPA was to promote the education of those involved with BPA and to help create standards for reporting, terminology, analysis and training.
How to determine bloodletting?
First, angle of impact and area of convergence needs to be determined. Then, the BP analyst will place their protractor at the blood stain location and project a string at the angle of impact in the direction of the area of convergence. Now, the string will show a general origin of the bloodletting.
How to determine area of origin of a BP?
To reliably determine the area of origin, the BP analyst needs to consider several blood drop stains, and these stains should ideally be from opposite sides of the pattern. Simply looking at a single drop isn’t enough to come to any reliable conclusion.
Why is a spherical pattern important?
spherical important for bloodstain pattern analysts? Because it helps them make an accurate calculation of the angle of impact when they analyze blood that has hit a surface after being in flight. Knowing the angle of impact is important for determining from which point or area the blood originated.
Why does blood form in flight?
Through experiments with blood, it has been shown that a drop of blood actually tends to form a sphere in flight. The formation is caused by surface tension, which is what holds the drop together.
What is blood stain pattern analysis?
Bloodstain Pattern Analysis is the study of the size, shape and location of bloodstains, in order to provide an interpretation of the physical events which gave rise to their origin.
Who interprets blood stain patterns?
Interpretation of bloodstain patterns and latent traces of blood which are found using luminol, should preferably be carried out by a trained bloodstain pattern analyst.
What is arterial spurting?
Arterial spurting. An arterial spurting (or gushing) pattern is a bloodstain pattern (s) resulting from blood exiting the body under pressure from a breached artery. On the photo below a pattern is shown that was made on a wall in a lab using a big syringe. Transfer patterns.
What is the blood spatter in a bullet?
Back spatter is blood directed towards the source of energy or force that caused the spatter. Due to the high speed and the power of the bullet, the blood spatter that is created is usually less than 2 millimeters. Sometimes the force that is carried out on the blood is so great, that a misting pattern is formed.
What is a wipe pattern?
A wipe pattern is a bloodstain pattern created when an object moves through an existing stain, removing and/or altering its appearance. On the photo a wipe pattern is shown where a person on his socks walked through wet bloodstains. Spill pattern. A spill pattern is a volume of blood that has fallen at once onto a surface.
What does it mean when a blood spatter is round?
The location where the blood spatter is more or less round shaped gives an indication of the height where the impact on the blood source has taken place.
What is void in blood?
A void is the absence of stains in an otherwise continuous bloodstain pattern. Photo 21 shows the location in the blue circle where a deceased victim bled severely before he died, leaving a void in the blood pool. Luminol is a chemical that luminescence’s in the presence of blood with a bluish light.
What happens when all the strings meet at the same point?
All of the strings meet at nearly the same point. Suddenly, an investigator begins recounting aspects of the crime: When it happened, where the assault took place in the room, what kind of weapon the perpetrator used and how close to the victim the assailant stood.
Why are strings important?
They're simply a tool to help investigators and analysts draw conclusions from a substance that's often found at crime scenes: blood. We've become used to hearing how specialists use blood samples to identify suspects through DNA. But the blood itself — where it lands, how it lands, its consistency, and the size and shape of its droplets, or spatter — can uncover a lot of significant aspects of the crime.
Is blood stain analysis a science?
Of course, analyzing blood spatter isn't as simple as fictional bloodstain pattern analysts like Dexter Morgan make it appear. Experts in the field often say that it's as much an art as a science. Although important aspects of bloodstain pattern analysis are well supported by research, analysts must be careful not to overreach [source: Iowa State ]. If the violent act involves multiple victims and multiple assailants, the challenge becomes even more complex. But a well-trained and seasoned analyst can provide key information that leads to arrest and conviction.
Blood in Flight
Area of Origin
- The area of origin is the three-dimensional space where the blood source was located when the blood began its journey. It is important to remember that bodies tend to be dynamic. Not only can the source of blood be engaged in major movements, but there are also small movements to take into account, such as the elasticity of skin. When a force is applied to the blood source (e.g. whe…
The String Method
- The string method is one of the oldest techniques for determining an space in which the bloodletting occurred, based on a bloodstain pattern. First, angle of impact and area of convergence needs to be determined. Then, the BP analyst will place their protractor at the blood stain location and project a string at the angle of impact in the direction of the area of converge…
Photographing Bloodstains
- Bloodstains at a suspected crime scene are typically photographed in three different ways, since each way has its pros and cons when its time to analyze the scene. Photographing the bloodstains is important for several reasons, and one of them is that a BP analyst might be unable to attend the scene personally and will have to relay on documentation, including photographs a…
Background
- Doctor Piotrowski
One of the earliest scientific studies of bloodstain patterns was made by Dr. Eduard Piotrowski of the University of Kraków in 1895. Even long before this study, bloodstain pattern analysis was sometimes used by law enforcement, but without much formal science to back it up. Dr. Piotrow… - LeMoyne Snyder
LeMoyne Snyder’s book “Homocide Investigation”, published in 1941, was widely used by forensic analysts of that era. It mentions bloodstain analysis, but only briefly. Examples of facts pointed out in the book are that bloodstains tend to fall in certain patterns based on the motion of an att…
Criticism
- A report released by the United States non-profit organization The National Academy of Sciences in 2009 highlighted several cases where blood splatter analysts had overstated their qualifications. The report also questions the reliability of BPA methods. Just as with many other forms of forensic evidence, bloodstain pattern analysis used in the legal system rests on the an…