Application of bloodstain pattern analysis (BPA) to reconstruct a staged crime scene in a complex forensic case.

Bloodstain Pattern Analysis (BPA) stands as a precious tool in the crime scene investigation and reconstruction, providing invaluable insights into the circumstances surrounding bloodshed. This comprehensive review delves into the profound significance of BPA, charting its evolution over time while spotlighting recent breakthroughs and identifying potential areas for further research and development, especially within the domain of digital technology. The fundamental essence of BPA lies in meticulously analyzing the form and dispersion patterns of bloodstains found at crime scenes., which aids investigators in comprehending the deposition of blood on evidence and shedding light on the movements and positions of the individuals and objects involved during the incident. Notably, BPA facilitates differentiating between accidents, homicides, and suicides, as well as identifying bloodstains left by criminals, thus playing a crucial role in ascertaining the circumstances surrounding an incident. Elements like blood velocity and the nature of the impacted surface significantly influence the size and shape of bloodstains, imparting crucial clues for an accurate crime scene reconstruction.A noteworthy application of BPA is in impact spatter analysis on hands, which holds importance for forensic ballistic examiner to recognize the firearm. Studies are discussed, related to sophisticated image processing and computerized techniques for BPA to scrutinize their reliability and accuracy. Cutting-edge advances have been witnessed in the field, including the application of Raman spectroscopy, automated methodologies, and the utilization of software programs like the FARO Scene program. These advancements have substantially elevated the efficacy and capabilities of BPA, empowering forensic investigators with enhanced analytical tools. Despite the remarkable strides made in blood spatter pattern analysis, the review underscores the abundant potential for continued research and development. In particular, refinements in methods for dating dried blood pattern and the evolution of automated techniques for crime scene reconstruction are prime avenues worthy of exploration.

Violent crimes are often pigeon-holed by bloodstain found at the crime scene. The science of analysing the bloodstains found at the crime scene is referred to as bloodstain pattern analysis (BPA). The bloodstain pattern analysis embraces analysts recognising and interpreting bloodstain patterns to uncover how they were bent, when they were created, who created them and what object was used. Bloodstain pattern analysis is an important technique for determining what happened at the crime scene and presenting answers to the crime that occurred. Bloodstain pattern analysis is a subfield of forensic science that utilises blood evidence to dive a conclusion about a crime and to illustrate the shadows of violent crimes. Though violent crime scenes that involve bloodshed often provide a prosperity of data in the form of the patterns, location, and possible causes of the bloodshed, it is unfortunate that such critical information can be missed and/or evidence demolished due to futile ways of protecting and preserving bloodstain patterns at the crime scene by the crime scene investigators from the Local Criminal Record Centre. The article took qualitative empirical approach where participants were interviewed with the permission obtain from South African police Services and ethical clearance acquired from the University of South Africa. Findings and recommendations in this article were significant for implementation by the police.

Application of multi-resolution 3D techniques in crime scene documentation with bloodstain pattern analysis

Chapter 3 - Physical Evidence

Crime scene investigation is usually the beginning point for successful use of physical evidence by forensic scientists, forensic experts, and forensic laboratory and criminal investigators in evaluating crime scenes. It is important to properly manage and investigate the scene of a crime in the best possible manner. Successful and high-quality crime scene investigation is a simple and methodical process. It follows a set of principles, proceduresIntroduction 55 Denition of a Crime Scene 56 Utilization of and Information from Physical Evidence in Crime Scene Investigation and Reconstruction 57Forensic Nursing and Crime Scene Investigations 58 General Crime Scene 59Crime Scene Procedures 59 Scene Management 59 Duties of First Respondent Law Enforcement 59 Securing the Crime Scene 59 Surveying the Crime Scene 60 Crime Scene Documentation 60 Crime Scene Searches 62Types of Physical Evidence at Crime Scenes 63 Transient Evidence 63 Patterned Evidence 64 Conditional Evidence 65 Transfer Evidence 66Crime Scene Reconstruction 66 Stages in Crime Scene Reconstruction 66Bibliography 67that are reasonable and ensure that all physical evidence is discovered and investigated, with the result that justice is served.

Bloodstain pattern analysis has become an arena of specialization in forensic sciences and deals with how bloodstains arise after blood is discharged from the body. This chapter offers the basic principles and common inferences behind bloodstain pattern analysis to give the reader general acquaintance to use at the crime scene. Bloodstain pattern analysis in its very core is based on the age-old Biblical dictum “Blood never lies.” The precise appearance and location of each bloodstain at a crime scene is very important. The blood follows the laws of fluid mechanics and responds under similar physical conditions that form the base of bloodstain pattern analysis. Therefore, each bloodstain pattern situated at a crime scene must be properly documented in notes, photographs, and sketches. Bloodstain pattern evidence requires much experience and testing of the surface characteristics of the target to determine how blood falling on that surface will behave. Bloodstain pattern interpretation courses are available, and it is highly recommended that such a course of study be taken prior to attempting this technique on actual casework. Training and experience will allow for the greatest amount of useful information to be derived from this technique.

As a result of its viscous nature, blood stain patterns formed from blood splatter makes blood one of the most common pieces of evidence encountered. Bloodstain pattern analysis (BPA) is a branch of forensic science that examines the physical properties of blood and uses graphical pattern recognition to map out and evaluate bloodstains found at crime scenes and crime scene reconstruction. Crime scene reconstruction ensures a better understanding of events that unfolded at a scene. However, health and ethical issues in using real blood during reconstruction have led scientist to search for alternatives to mimic blood. An investigation using henna dye to mimic bloodstain by dropping from different heights (3 to 7 feet) was carried out in an outdoor crime scene simulation area. With the necessary steps involved in post scene processes diligently followed, it was observed that at 3 the formation of insignificant satellites with small spines around each drop, at 4 feet minimal satellite stains and longer spines appeared, at 5 feet very small spines and minimal satellites were observed with an elongation on parent droplet, at 6 feet shows more distant longer satellites and at 7 feet tiny elongated droplets observed with satellites and had smaller droplet attached. It was concluded that when the height of dropping fake blood is increased, the distance of satellite stains emerging from the fake bloodstain also increases. Therefore the bloodstain pattern formed is dependent on the height of the blood spatter on a horizontal surface. Therefore henna could be used to for investigations of crime scenes and educational studies on bloodstain pattern analysis (BPA).

When it is determined that there are or should be traces of blood at the crime scene, it is necessary to take search measures of the crime scene and visualize such traces. The next important step is documenting these clues by description, criminal photography, sketching and video made to make them available for potential additional analysis in the later stages of criminal investigation or criminal procedure. Traces of blood are found in many criminal offenses and can be important evidence. It would be a crucial mean, when combined with the information derived from any DNA analysis, to allow an investigator to corroborate or refute specific investigative theories and subsequent statements offered by suspects, victims, and witnesses. So, the current study aim to clarify the crime scene investigation and reconstruction for detecting bloodstain patterns; specific skills of criminalist for analyzing blood traces; different means for interpreting such traces; blood factor and types as important tools in criminal investigation for blood patterns. Keywords: Blood; Crime Scene; Trace

Effect of yarn structure on wicking and its impact on bloodstain pattern analysis (BPA) on woven cotton fabrics

Crime scene photography plays a fundamental role in forensic investigations. Its primary purpose is the recording of the entire crime scene, both the context and specific details, for later recollection, analysis and presentation. Bloodstain pattern analysis (BPA) relies extensively on the recording of context and detail. This study evaluated the use of panoramic imaging for the recording of impact patterns at crime scenes to support the off-site determination of area of origin (AO). This evaluation used a commercially available hardware system that consisted of a robotized, tripod-mounted platform, interfaced with a digital camera, to provide an automated panoramic image capture process. Software was subsequently used to construct a digital panorama. Bloodstain pattern analysis software was then used for the off-site determination of AO from the panoramic image. The results of this research demonstrated that the developed method can be employed to effectively capture a panoramic image of an impact pattern with sufficient detail for accurate AO determination. The approach can enable crime scene officers to record impact patterns without extensive training on BPA or the recording of blood spatter. The approach also enables BPA experts to digitally analyse spatter information from a single image as opposed to evaluating multiple photographs.

Bloodstain pattern analysis has become a field of specialization in Forensic sciences and plays an important role in the reconstruction of events at a crime scene. Research, books, and articles have been published on the analysis and interpretation of bloodstain patterns We present a case study of a road traffic accident in which bloodstain pattern analysis helped us to solve the discrepancy between reports produced by forensic examiners and by the forensic biology department. The case was of a 22-year-old man who died immediately and a 31- year-old woman who survived a road traffic accident. They were both found outside their overturned car and it was impossible to ascertain from initial observations which of the victims was driving the car at the time of the accident. An external examination of the man revealed multiple injuries, and the cause of his death was severe brain injury. The woman survived with a fracture of the forearm, dislocated clavicle bone, and other minor injuries. After initial examination of the car and based on the pattern of injuries the deceased received, forensic examiner concluded that the man was the driving the car at the time of accident. On the other hand, the forensic DNA analysis of bloodstains obtained from the driver's seat matched that of the woman, suggesting that she was the driver. This apparent discrepancy directed the forensic examiner to carry out a bloodstain pattern analysis on the driver's seat. The bloodstain pattern analysis helped resolve the discrepancy and enabled the investigators to identify the driver correctly. This case report emphasizes the importance of bloodstain pattern analysis in the reconstruction of cases involving road traffic accidents.

We explore for the first time the effect of medical drugs on Bloodstain Pattern Analysis (BPA). The widely administrated anticoagulant warfarin is examined with its effect on blood viscosity measured using a capillary tube viscometer over the range of 10−6 M to 10−4 M, representing therapeutic to fatal levels respectively. We find that the administration of therapeutic to fatal doses corresponds to a viscosity change of 3.6 to 20.4% respectively. Additionally the effect of warfarin on blood's surface tension, usually assumed to be constant, is examined over the therapeutic and fatal dosage range, which was found to result in a change of between 0.6 and 4.7% respectively. The observed variability's were integrated into previously derived BPA equations used for de-convoluting various parameters where convincing evidence is shown that drug contaminated blood induces a variation of 1.23 mm (5.93%) in the determined final stain diameter leading therefore to the possible misinterpretation of bloodstains found at Crime Scenes and consequently inaccuracies to occur in crime scene reconstruction. This work offers insight into whether medical drugs play a significant role in the possible misinterpretation of bloodstain evidence.

Bloodstain Pattern Analysis (BPA) involves the interpretation of distinct blood patterns found at crime scenes after a bloodletting incident. Much time and research has been dedicated to the quantification and analysis of blood due to its occurrence at crime scenes, establishing ways in which to map the sequence of events and general movement within the crime scene. In this paper we explore the fundamental mechanism of drying blood and the effects of packed cell volume percentage (PCV%) upon BPA investigations. Since PCV% can fluctuate between 15–75%, and in turn directly affect blood viscosity, it is important to consider its impact when evaluating bloodstains. Specific packed cell volumes (PCV%) between 15 and 75% were investigated, relating to the highest and lowest levels found in potential victims or suspects. Observations illustrated the appearance of the “coffee-ring” effect as an important mechanism of drying blood, building a thicker outer ring of red blood cells as the drop evaporates and dries, the so-called the blood ring effect. There was also found to be a significant difference in the appearance of the final bloodstains when comparing PCV%. Owing to the lower PCV% being made up of mainly plasma, bloodstains became more transparent under microscopic observation. The opposite conclusions can be made for higher PCVs where bloodstains were much thicker around the periphery of the stain. Crime scene relatable drying studies were also considered; skeletonization (relating to drying time) and volume estimation were all investigated in relation to PCV%. Three volume estimation studies were performed: dry weight, scaled photographs and spectrophotometry. It was found that all were unsuitable for volume estimation, when considering PCV% and surface type. Since PCV% cannot be established in dried blood, these volume estimation methods should not be used as the errors would be too great. Skeletonization (drying time) was not altered by PCV%.

Proficiency testing is required to ensure quality, efficiency, and safety in many disciplines. Multiple proficiency tests exist for forensic disciplines such as fingerprint analysis and toxicology, but minimal research has been conducted on the proficiency of crime scene experts. The foundation of an effective proficiency test rests upon the development of competency tests. Here, a proof-of-concept competency test was designed as an example of how to evaluate the crime scene processing skills of forensic identification officers (FIOs) using a mock crime scene scenario. The test has three main components: i) crime scene approach test, ii) evidence processing test, and iii) general crime scene knowledge test, with pre-test demographic questions. The competency testing content and process was reviewed by two forensic identification experts (manuscript co-authors) for viability. Due to its digital format, this competency test is widely accessible, user-friendly, and can be a template for a police service to develop their own crime scene competency test or an internal proficiency test for specialized tasks such as a fingerprint comparison or an estimation of the area origin in bloodstain pattern analysis (BPA) to help mitigate risks and identify knowledge gaps.

3D bloodstain pattern analysis: Ballistic reconstruction of the trajectories of blood drops and determination of the centres of origin of the bloodstains