Public discourse on crime often occurs in digital communities where internet users engage in ‘online sleuthing’ to investigate crimes and identify suspects (Wästerfors et al., New Media & Society 26:6289–6306, 2024). The origin of these communities is tied to social media where armchair detectives search for information, comment, share, debate and theorise evidence and attempt to engage with law enforcement agencies in a form of ‘true crime infotainment’ (Yardley et al., Crime, Media, Culture 14:81–109, 2018). However, similar public interventions existed prior to the advent of social media. In the 1980s, supporters of Lindy Chamberlain analysed and debated the evidence for and against the woman at the centre of Australia’s infamous ‘dingo baby case’ in newsletters and booklets now archived at the State Library of New South Wales (SLNSW), Australia. Despite its modest size, the collection holds historical and cultural significance for evidencing public participation in the governance of crime and attempts to seek redress for Lindy and her then husband Michael who suffered Australia’s greatest miscarriage of justice. The archive materials question conventional assumptions about the origins of contemporary online sleuthing, emphasise the cultural importance of the Chamberlain case even after four decades and highlight the significant role ordinary members of the public played in shaping its outcomes.