Since the early 2000s, forensic science has achieved extraordinary public visibility and an equally extraordinary legitimacy, even in courts (this is the so-called ‘CSI effect’), the assumption being that persons may lie, but that physical facts revealed by forensics speak the truth. Despite this, forensic science has not escaped some more critical inquiries. Alongside these developments rooted mostly in popular culture, cognitive psychologists started to identify cognitive biases among forensic practitioners and a small number of historians of science began to excavate the histories of some of the most prominent forensic techniques, in particular fingerprint analysis (e.g. S.A. Cole, Suspect Identities: A History of Fingerprinting and Criminal Identification (2002)), casting severe doubts on the reliability of several of these techniques. In the past decades, historians of science have also become much more attuned to how local contexts shape epistemic practices, but this insight has not been applied widely to forensic science (but see I. Burney and C. Hamlin (eds.), Global Forensic Cultures: Making Fact and Justice in the Modern Era (2019)). Trais Pearson's fascinating book on the politics of death in the Kingdom of Siam convincingly demonstrates the power of this type of analysis.

Siam (the country changed the name to Thailand in 1939) offers an excellent case study on how local circumstances interacted with outside influences in shaping forensics. Owing to Siam's geographical location in the centre of continental South East Asia, Great Britain and France left the country as a buffer state between their colonies in Burma, Malaya and Indochina. Despite retaining its independence, Siam's economic and political development was still made to feel the influence of these colonial powers, especially Britain. It became subject to unequal trade treaties, which had significant negative effects on its economic development. These treaties established extraterritorial legal rights for foreign residents, i.e. they were subject to the laws of their home countries, not to the laws of Siam, and jurisdiction lay with consular courts. The Siamese state reacted to these developments by adapting its administration – but also certain cultural mores like marriage laws (see T. Loos, Subject Siam: Family, Law, and Colonial Modernity in Thailand (2006)) and dress codes – to Western models in order not to be perceived as ‘uncivilized’.

Pearson relates a key episode in the process of legal modernization in Siam: how did the Siamese state become interested in the fate of its dead and injured subjects and how were progressively more systematic ways established in which the causes of their death or injury were examined? The author first describes traditional Siamese understandings of unnatural death and its causes. ‘Inauspicious’ or ‘bad’ deaths were characterized by the impaired consciousness of the deceased at the time of death – whether from murder, drowning, suicide, accident and so on – which meant that the impaired consciousness could not move on in the process of reincarnation and could become a malevolent spirit, bound to the place of death and a risk to the community. Restorative action – through appropriate rituals – was the responsibility of the deceased's family. The well-being of the community, not forensic and legal certainty, was the focus of actions surrounding unnatural deaths. In the 1890s, the Siamese state started to show stronger interest in unnatural deaths, especially by compiling these deaths in a file called ‘Deaths by various causes’, but police investigations remained cursory and improvisational. Still, Siamese state officials seized the authority to interpret unnatural, suspicious deaths, but this executive authority very soon faced another challenge.

This development is partially explained by the presence of a large European and American expatriate community in nineteenth-century Bangkok, considerably augmented by subjects hailing from European colonies in South East Asia – both groups beneficiaries of extraterritoriality – who were bound to come into conflict with Siamese subjects, in both criminal and civil matters. The granting of a concession in 1887 to two Danish entrepreneurs to form the Bangkok Tram Company and to operate trams in Bangkok provides Pearson with a rich source of material on accidents and ensuing legal proceedings. As in Europe, passenger rail travel challenged ideas of responsibility for accidental death, and new assumptions about risk and liability took root. These assumptions also became established in the consular courts in Siam, which ruled on cases involving the Bangkok Tram Company. These courts, however, privileged Western litigants as they could often hope for large indemnities, while the Bangkok Tram Company compensated Siamese victims with irregular and ad hoc compensations, which harked back to the traditional practice of indemnification.

Forensic medicine was an authoritative form of knowledge that could be used to reinforce the social and legal privileges enjoyed by foreigners. The unequal treatment of the dead and injured in this plural legal environment drove officials in the Siamese bureaucracy to turn to new forms of medical and medico-legal expertise. This mirrored earlier turns to new forms of expertise, especially in mapping and law, intended to strengthen the Siamese state's claim to sovereignty. Forensic inquests needed to produce appropriate evidence so that consular courts could no longer dismiss criminal complaints against foreign residents suspected of having harmed Siamese subjects. The last chapter of the book recounts the fascinating story of the first two practitioners of forensic inquests in Siam – the British doctor Percy A. Nightingale and his Siamese assistant Mo Meng Yim. Both had impeccable credentials and the required expertise, and Meng Yim managed to translate the findings into an idiom comprehensible to the Siamese bureaucracy. During two inquests at the end of the nineteenth century, the two doctors produced documentary evidence acceptable to the standards of the consular courts. This episode was, though, short-lived – Nightingale returned to England and from then on medical experts recruited from abroad focused more on issues of public health. The Siamese administration counted deaths and recorded their causes, but the main concern was health at the level of the population and not anxieties about limited sovereignty.

Pearson presents a compelling study of medico-legal practices and legal subjectivity in an environment characterized by limited sovereignty and transnational flows of expertise, while at the same time giving space to subaltern voices. This book is a noteworthy contribution to studies of medicine, law, society and politics in the colonial and semi-colonial worlds.