Modeling human movement and mechanics: thoracic cage

Abstract Computer-generated models have revolutionized how reconstructions of violent events, such as police use of force, are both performed and visualized. Yet, many experts in the legal and forensic disciplines do not understand them at a level required to use them effectively or create credible arguments supporting their findings. Simply put, models are a simplification of reality. Hence, models permit human programmers to specify the simplified behavior of a system. Since model parameters dictate the system's behavior, the programmer must document and provide justification for the selection of model parameters. The model structure, together with the selected parameters, form the backbone supporting the forensic investigator’s conclusions. This paper will begin with an overview of the usefulness of models in forensic investigations and follow with an example of how a model is constructed and applied in use of force cases. The selected cases are particularly relevant to incidents commonly encountered in law enforcement, frequently leading to litigation.