Studying asphyxiation in the lab: the role of experimental evidence in cause-of-death inquiry

Like most scientific and medical disciplines, forensic medicine employs evidence from experimental studies. Yet, unlike most disciplines, forensic medicine is primarily interested in the post-hoc evaluation of individual causal claims. How does experimental work that is performed under laboratory conditions bear on the assessment of field cases? We argue that experimental studies in forensic medicine help identify or exclude potential causes of death. Potential causes will not explain why an individual died. Yet they can be important to rebut claims to the impossibility of a certain course of events. We support our argument by looking at experimental studies of asphyxiation. These studies have been central to recent academic and public debate of death-in-custody. While some take the studies to show that restraint positions employed by law enforcement can cause death, others dispute this. We analyze the causal claims put forward by experimental asphyxiation studies and show that some attempts to disprove the risks associated with restraint positions involve 'false advertising': a mismatch between the study's methodology and its purported goals.