Blood stain pattern analysis

Abstract

Bloodstain pattern analysis (BPA) refers to the collection, categorization and interpretation of the shape and distribution of bloodstains connected with a crime. These kinds of stains occur in a considerable proportion of homicide cases. They offer extensive information and are an important part of a functional, medically and scientifically based reconstruction of a crime. The following groups of patterns can essentially be distinguished: dripped and splashed blood, projected blood, impact patterns, cast-off stains, expirated and transferred bloodstains. A highly qualified analysis can help to estimate facts concerning the location, quality and intensity of an external force. A sequence of events may be recognized, and detailed questions connected with the reconstruction of the crime might be answered. In some cases, BPA helps to distinguish between accident, homicide and suicide or to identify bloodstains originating from a perpetrator. BPA is based on systematic training, a visit to the crime scene or alternatively good photographic documentation, and an understanding and knowledge of autopsy findings or statements made by the perpetrator and/or victim. A BPA working group has been established within the German Society of Legal Medicine aiming to put the knowledge and practical applications of this subdiscipline of forensic science on a wider basis.

Crime scene and body alterations caused by arthropods: implications in death investigation

“…Among these, 7 were case reports [13][14][15][16][17][18][19], 3 case series [6,20,21], 19 original articles [22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40], 4 were technical notes [41][42][43][44] and 8 were reviews [1,10,[45][46][47][48][49][50].…”

“…The information obtained by BPA can be used for the reconstruction of the manner of death and the evaluation of other primary issues related to the death, such as the victim's and perpetrator's position and movement before and after committing the crime and the assessment of witnesses' statements [48].…”

“…transfer, contact and drip patterns, expired blood or high velocity spatter), and they could allow the reconstruction of the criminal acts [19,48,51]. Problems can arise when other modifications, such as those produced by the insect activity, alter the bloodstains and consequently their interpretation.…”

Hyperspectral imaging for non-contact analysis of forensic traces

“…In these applications, the added spatial information is crucial, as the blood stain pattern may reveal useful information for the reconstruction of a crime [69]. The spectroscopic identification of other body fluids [70] will also benefit from HSI, as the traces can then be interpreted in their original context.…”

Interpretação do Padrão das Manchas de Sangue em um Caso de Homicídio em Local Inidôneo

“…A morfologia das manchas de sangue varia conforme a altura, as angulações e a velocidade das projeções do ponto hemorrágico, além das características dos suportes em que as manchas foram projetadas e se encontram impregnadas na cena 3 . Pela importância que as manchas de sangue representam no contexto das investigações periciais envolvendo locais de morte violenta, sua análise na cena de crime permite inferir sobre o tipo de arma utilizado na ação e a quantidade de golpes desferidos contra a vítima; inferir sobre o ponto de convergência dos impactos e o posicionamento dos indivíduos envolvidos no evento; tipos de lesões; tempo decorrido dos fatos; estabelecer a dinâmica dos acontecimentos; e até mesmo permitir a identificação da vítima e da autoria do delito, por meio do levantamento do perfil genético [4][5][6] . Dessa forma, as características das manchas de sangue podem definir padrões, identificando a natureza do evento que as originou e fornecendo informações importantes sobre a ocorrência 1,6 .…”