title: Bloodstain Pattern Analysis: implementation of a fluid dynamic model for position determination of victims.
abstract: Bloodstain Pattern Analysis is a forensic discipline in which, among others, the position of victims can be determined at crime scenes on which blood has been shed. To determine where the blood source was investigators use a straight-line approximation for the trajectory, ignoring effects of gravity and drag and thus overestimating the height of the source. We determined how accurately the location of the origin can be estimated when including gravity and drag into the trajectory reconstruction. We created eight bloodstain patterns at one meter distance from the wall. The origin's location was determined for each pattern with: the straight-line approximation, our method including gravity, and our method including both gravity and drag. The latter two methods require the volume and impact velocity of each bloodstain, which we are able to determine with a 3D scanner and advanced fluid dynamics, respectively. We conclude that by including gravity and drag in the trajectory calculation, the origin's location can be determined roughly four times more accurately than with the straight-line approximation. Our study enables investigators to determine if the victim was sitting or standing, or it might be possible to connect wounds on the body to specific patterns, which is important for crime scene reconstruction.
authors.affiliation: 1] WZI, IoP, University of Amsterdam, Science Park 904, Amsterdam, Netherlands [2] Netherlands Forensic Institute, Laan van Ypenburg 6, The Hague, Netherlands.
authors.forename: Nick
authors.initials: N
authors.lastname: Laan
authors.affiliation: Netherlands Forensic Institute, Laan van Ypenburg 6, The Hague, Netherlands.
authors.forename: Karla G
authors.initials: KG
authors.lastname: de Bruin
authors.affiliation: WZI, IoP, University of Amsterdam, Science Park 904, Amsterdam, Netherlands.
authors.forename: Denise
authors.initials: D
authors.lastname: Slenter
authors.affiliation: 1] WZI, IoP, University of Amsterdam, Science Park 904, Amsterdam, Netherlands [2] Mechanical Engineering, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand.
authors.forename: Julie
authors.initials: J
authors.lastname: Wilhelm
authors.affiliation: Mechanical Engineering, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand.
authors.forename: Mark
authors.initials: M
authors.lastname: Jermy
authors.affiliation: WZI, IoP, University of Amsterdam, Science Park 904, Amsterdam, Netherlands.
authors.forename: Daniel
authors.initials: D
authors.lastname: Bonn
mesh_terms: D001801:Blood Stains; D019548:Crime Victims; D003890:Desiccation; D006801:Humans; D057446:Hydrodynamics; D008962:Models, Theoretical