An innovative imaging method for recording bloodstain patterns at crime scenes using panoramic imaging

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.

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.

Implications of two backward blood spatter models based on fluid dynamics for bloodstain pattern analysis

Bloodstain pattern analysis can provide insight into a sequence of events associated with a violent crime. However, bloodstain pattern analysis can be confounded by the feeding activity of blow flies. We conducted two laboratory experiments to investigate the relationships between Lucilia sericata (green bottle fly) and Calliphora vicina (blue bottle fly), expirated bloodstains, and pooled bloodstains on a range of surfaces (linoleum, wallpaper, textured paint). C. vicina and L. sericata changed bloodstain pattern morphology through feeding and defecation. They also deposited artifacts in rooms where blood was not present originally. Chemical presumptive tests (Hemastix(®) , phenolphthalein, leucocrystal violet, fluorescein) were not able to differentiate between insect artifacts and bloodstains. Thus, C. vicina and L. sericata can confound bloodstain pattern analysis, crime scene investigation, and reconstruction. Crime scene investigators should be aware of these fundamental behaviors, and the effects that blow flies can have on expirated and pooled bloodstain patterns.

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

In recent years, crime scene analysis has been transitioning from being a technical discipline to being a scientific process. This progression is shifting the forensic practitioner examining crime scenes into a deeper level of scientific reasoning. This study evaluates the use of reasoning by practitioners in the disciplines of crime scene investigations and bloodstain pattern analysis. A well-established classroom test of scientific reasoning (CTSR) was distributed online to active crime scene investigators (CSI) and bloodstain pattern analysts (BPA) (n = 213) using Qualtrics software. The survey provides quantitative data on the reasoning ability of the participating practitioners along with demographic information on education, employment status (specifically, police or civilian), and work experience. Linear regression analyses indicate that there is a significant difference between the CTSR scores and education level. The higher educated practitioner (graduate level) performed better on the reasoning test. No significant differences were found between the test scores and the years of experience, even when sectioned into 5-year increments of 5 to 25+ years of experience. Similarly, there was no difference between the test scores and employment status for the CSI group and within the BPA group. This information suggests that the level of education plays the most important role in the development and use of reasoning skills, whereas experience and employment status are not as influential. The test scores were also mapped to Piaget’s categories – concrete operational, transitional and formal operational reasoners – with 69.5% of CSI and 77% of BPA scoring as formal operational reasoners. The authors recommend that a CTSR be used for testing current and future (tertiary forensic students) practitioners for evaluating reasoning skills and identifying scientific learning gaps. This study also supports further research into forensic epistemology and pedagogy, to deepen our knowledge of science in forensic science.

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).

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

Fire is often used to conceal or destroy evidence of violent crimes, making it essential to understand how fire environments affect forensic evidence, particularly bloodstain patterns. This study investigates the impact of high heat environments and fire on the morphology and analysis of bloodstain patterns. Using controlled fire exposure, bloodstains were analyzed pre‐ and post‐fire exposure on various substrates, including glass, painted drywall, and painted plywood. Measurements of angle of impact (AOI) and area of origin (AOO) were conducted using Faro Zone 3D Expert software. Despite physical alterations due to extreme temperature exposure, certain characteristics of the original bloodstains persisted. AOI calculations showed minimal deviation between pre‐ and post‐fire measurements, with standard deviations generally under two degrees. AOO estimations also demonstrated no substantial statistical differences between pre‐ and post‐fire data. The study confirms that bloodstain patterns retain observable traits despite exposure to high heat conditions, supporting the reliability of BPA in fire‐affected scenarios. These findings enhance the understanding of bloodstain behavior in fire environments, aiding forensic investigations in accurately analyzing bloodstain patterns in cases involving fire or high‐temperature conditions.

Bloodstain pattern analysis (BPA) is the forensic discipline concerned with the classification and interpretation of bloodstains and bloodstain patterns at the crime scene. At present, it is unclear exactly which stain or pattern properties and their associated values are most relevant to analysts when classifying a bloodstain pattern. Eye tracking technology has been widely used to investigate human perception and cognition. Its application to forensics, however, is limited. This is the first study to use eye tracking as a tool for gaining access to the mindset of the bloodstain pattern expert. An eye tracking method was used to follow the gaze of 24 bloodstain pattern analysts during an assigned task of classifying a laboratory-generated test bloodstain pattern. With the aid of an automated image-processing methodology, the properties of selected features of the pattern were quantified leading to the delineation of areas of interest (AOIs). Eye tracking data were collected for each AOI and combined with verbal statements made by analysts after the classification task to determine the critical range of values for relevant diagnostic features. Eye-tracking data indicated that there were four main regions of the pattern that analysts were most interested in. Within each region, individual elements or groups of elements that exhibited features associated with directionality, size, colour and shape appeared to capture the most interest of analysts during the classification task. The study showed that the eye movements of trained bloodstain pattern experts and their verbal descriptions of a pattern were well correlated.

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.

Bloodstain pattern analysis—Casework experience

Bloodstain pattern analysis can be critical to accurate crime scene reconstruction. However, bloodstain patterns can be altered in the presence of insects and can confound crime scene reconstruction. To address this problem, we conducted a series of controlled laboratory experiments to investigate the effect of Lucilia sericata (Meigen) on impact bloodstains and pooled bloodstains in association with three combinations of common surfaces (linoleum/painted drywall, wood floor/wallpaper, and carpet/wood paneling). L. sericata fed from the pooled bloodstains and added insect stains through regurgitation and defecation of consumed blood. L. sericata formed defecatory trails of insect stains that indicated directionality. Defecatory stains fluoresced when viewed at 465 nm with an orange filter. These observations differed from Calliphora vicina insect stains because feeding on blood spatter was not observed and trails of insect stains were formed by L. sericata. The fluorescence of defecatory stains can be used as a method to detect insect stains and discriminate them from real bloodstains.

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.