Although not true spatter, another pattern often confused with spatter is the "fly speck" or "fly spot" pattern. Flies present within the scene will feed on blood found there. This blood is both tracked about and regurgitated by the flies.
In the instance of the tracking pattern, the marks are extremely small but a pattern may be evident on close examination. In the case of regurgitation, the specks are remarkably symmetrical Most often, the analyst finds these patterns in warm areas where the flies rest, such as high in window corners or along walls where the sun strikes.
Such stains will usually test positive for blood with a presumptive test. Obviously, care should be exercised in evaluating any abnormal patterns which meet these criteria. However, no integrated approach by natural sciences and criminalists had been used until actual case work see cases below and presentation in courts, made it necessary to develop a method to safely distinguish between blood spatter caused by force and blood spatter-like patterns produced by flies. This leaves recognition of stain patterns and other physical information as the relevant criteria.
The following text illustrates stains produced by the activity of flies and suggests methodology for evaluating stains in a decomposed body scene. Furthermore, from the above quotes it appears that some documentation of the crate was possible. In many countries, it is however unlikely that a blood stain pattern expert will enter he actual scene and therefore, documentation of crates has, to our knowledge and does usually never take place.
Blood that is subjected to a low velocity impact less than 1. It is caused by free-falling blood under the influence of gravity, including blood cast off from fist shoe, or weapon. Blood spatter as reported in the following three cases was usually thought to be caused be either high velocity impact, or by a mixture of medium to high velocity impact.
Those types of spatter are defined as blood subjected to a medium velocity impact about 7. The remains of two men were discovered at hrs on June in in a third level apartment in a five-plex apartment building in urban Lincoln, Nebraska, USA . Both victims were fully clothed; both had a gunshot wound to the head and gunshot wounds to the torso. One victim was found face down in the kitchen area and the other victim was prone on the living room floor on carpeting. Pools of a reddish substance were observed around the bodies of the victims. The bodies were in the active decay stage with black putrefaction only just beginning; the skin was intact everywhere except where there were gunshot wounds.
At the wound sites, there was dried blood and body fluids and in the areas around the bodies, flies, maggots and pupae as well as some adult flies were present. On June , at hrs, the police collected six adult flies, three third instar fly larvae and several hundred first instar fly larvae in ethanol from the scene.
Adult flies had probably gained access to the apartment by an open space beneath the front door. Both adults and larvae were identified as Phormia regina MEIGEN Diptera:Calliphoridae , the black blowfly and concluded from the presence of small, first instar larvae and large, third instar larvae that two distinctly separate periods of egg-laying by adult flies had taken place. Initial observation of the scene gave the appearance of extensive low, medium and high velocity blood spatters.
Above the position of one of the victims numerous stains of the low-high velocity type were found fig. Similar areas were found on a kitchen hanging lamp, the interior and exterior of the entry door, the bathroom, the two bedrooms and the walls around the victims. The first assumption to be made was that there had been slinging of a lot of blood around the kitchen and living room.
This would suggest not only gunshot wounds, but considerable movement of the victim and suspect s. It could suggest a motive of robbery, burglary, assault, or a surprise attack. Examination of the kitchen and living room did neither indicate struggling or fighting to any great amount. In the bedrooms and bathroom there were flies, but no signs of bloodstain patterns.
There were no maggots in these rooms. The conclusion we made was that not much activity had taken place in the bedrooms or the bathroom of an assaultive nature and the bloodshed had taken place in the kitchen and living room.
Recostructing the angle of impact of many of those stains, however, led nowhere. There was no indication that the bodies had been moved and there were no signs of a struggle in the bedrooms, or bathroom. Furthermore, stains of a sperm-like shape irregular, uneven form with tail much longer than the body as well as a missing systematic directionality were observed.
Since all stains were composed of blood, how did they a get into all of the rooms and b transferred to the walls? It is known that after feeding, flies regurgitate and defecate. Hence, flies could have caused stains, containing blood of the victims, by regurgitation, defecation and transference. In such cases, it is expected that presumptive blood tests would indicate the presence of blood.
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Such a high value will not be reached unter most case conditions, especially since not only the calculated angles of impact but also the directionality of the stains never point into one direction as would be expected from a violent impact on a source of blood. Also, a mixture of round, symmetrical and teardrop-like stains was found to be highly suspicious for fly activity fig. In this experiment, orientation was directed into the following directions: However, single stains will not provide results that are statistically sound.
Although the ratio does not conclusively identify a stain as a fly artifact, it provides a tool to eliminate suspect stains see also 5. With information that stains appearing as human blood spatters were fly artifacts, coupled with other scene evidence, we felt confident that the possibility of an execution or revenge slaying could be put into the mix of suspect behaviors at our crime scene. In Summer , a dead female person was found in her bedroom in an urban appartment in Cologne, Germany. The body had entered dried-out state of decay with severe undernourishment during lifetime and an underlying minimal greenish discoloration of the face and the abdominal area after death.
Identification of blood stains under different environmental conditions
In the anal region of the corpse, few blow fly maggots oldest larval stage L3 were found. As soon as the windows were opened, adult Lucilia sp. Therefore and because of numerous dots in the face of the dead person, the police asked if blow flies had been present, or if those dots had to be attributed to a source to be investigated on.
The windows were closed before the police entered which explained the presence of only few flies, mostly pupae of phorids Diptera: Phoridae , was in accordance with the reconstruction of events. Apart from piles of empty pizza delivery cardboard boxes and cigarette butts, which did not provide food sources for blow flies, the appartment was very clean and expensively furnished. The bathtub was half filled with discolorated water that was most likely used to wash clothing.
Since the entrance door was regularly locked and no signs of a violent fight were present, a reddish spatter field at a fan chain in the kitchen became of interest fig 3 c,d. The kitchen was located two rooms away from the sleeping room and there was no visible evidence that linked the kitchen to any violent event. Closer examination led to the conclusion that the stains were fly artifacts.
Since the eyes of the corpse were still intacts and not used as a food resource by maggots, it was concluded that only very few adult individuals of a smaller fly species had been living in the appartment at some point before, or at the time of death.
Blood Stain Identification and Interpretation – Crime Scene Archaeology
Those few individuals used the fan chain as a resting place and deposited reddish material with a typical preference fort he lower border of the surface. The same effect is present in fig. Because of the nature of the stains, they were neither taken into account for the further police investigation nor the reconstruction of the events at the scene.
The case was considered to be self neglect in contrast to killing, or neglect by another person. January , the dead bodies of a mother and her child were found in the living room of their house on the border of the city of Cologne, Germany.
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They had been dead for around six hours. Another child that had been sleeping upstairs was alive and not hurt. Blood stain patterns were used to determine the course of events. The crime scene reconstruction based on blood spatter became important to check the statements of an accused man who owned a knife that was used for the stabbing.
For legal technicalities rights of inheritance it also became important if the woman, or her child had been killed first. Thridly, the defense lawyer wanted to proof that his client had stabbed the child with brutal force to make clear that his client had no mental control in the moment he performed the stabbing. Apart from medico-legal considerations, it was thought that the velocity of the blood spatter might help to address theses questions.
Amongst numerous other reddish stains in the house in this case, due to a local police procedure, all stains determined as originating from the victims by DNA typing , few very small stains on a lamp were observed. This lamp was located only ca. The police asked if these stains were caused by the impact of violence, or by flies. As in most cases, the presence of flies was not looked at by the first team which entered the house through a window. After that, all flies may have flown out of the window.
Therefore, a combined blood spatter and forensic entomology expert statement was asked for by the police and later again requested by the judge during the trial. The tiny, round stains on the lamp were distributed over the complete surface fig. In , Dr. Paul Kirk of the University of California at Berkeley prepared an affidavit regarding his findings based upon bloodstain evidence to the Court of Common Pleas in the case of the State of Ohio vs. Samuel Sheppard. This was a significant milestone in the recognition of bloodstain evidence by.
Kirk was able to establish the relative position of the attacker and victim at the time of the administration of the beating. He was also able to determine that the attacker administered blows with a left hand, which was significant in that Dr. Sheppard was right-handed. The further growth of interest and use of the significance of bloodstain evidence is a direct result of the scientific research and practical applications of bloodstain theory by Herbert Leon MacDonell Figure 1. Through the assistance of a Law Enforcement Assistance Administration LEAA grant, MacDonell conducted research and performed experiments to re-create and duplicate bloodstain patterns observed at crime scenes.
This resulted in his publication of the first modern treatise on bloodstain interpretation, entitled Flight Characteristics of Human Blood and Stain Patterns Figure 1. Department of Justice. MacDonell organized formal instruction for investigators in bloodstain interpretation through bloodstain institutes conducted throughout the United States and abroad and has trained hundreds of police investigators, forensic scientists, and crime laboratory personnel at these institutes.
As a direct result of MacDonell s efforts, the state of the art of bloodstain interpretation in forensic science has increased considerably and others continue to make contributions to the field in crime scene reconstruction, teaching, and publications. In , Terry L. Laber and Barton P. Eckert and Stuart H. James was published in This work included numerous case studies involving bloodstain pattern interpretation. Tom Bevel and Ross M.
Gardner co-authored the text entitled Bloodstain Analysis With An Introduction to Crime Scene Reconstruction in Scientific articles pertaining to aspects of bloodstain pattern interpretation are gaining increasing visability in well-known publications including the Journal of Forensic Sciences, the American Journal of Forensic Medicine and Pathology, the Journal of the Canadian Society of Forensic Science, and the Journal of Forensic Identification.
IABPA publishes a newsletter on current bloodstain topics and schedules of training courses and explores such issues as the curriculum for basic instructional courses in bloodstain interpretation, uniformity in bloodstain terminology and research in the field. The yearly IABPA conference agenda includes numerous case presentations and research topics by members and guest lecturers.
Objectives of Bloodstain Pattern Interpretation Bloodstain pattern interpretation is a discipline which utilizes the sciences of biology, physics, and mathematics.
Related Interpretation of Bloodstain Evidence at Crime Scenes, Second Edition
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