This article addresses a frequently asked question regarding Hong Kong policing since the outbreak of prolonged civil unrest in June 2019: How can we understand the tactics adopted by the police in their attempts to de-escalate street violence, and why did the highly regarded police quickly lose its legitimacy among the public? This article argues that these phenomena can be explained by the abrupt change in the structural and policing context. This combined and interacted with the limitations of the ‘paramilitary policing model’ and public order legislation of Hong Kong adopted since the realignment of Beijing’s Hong Kong policy under the ‘One Country Two Systems’ principle in 2012. In the face of growing resistance to change this shift demystified the ‘professionalism’, ‘neutrality’, and ‘accountability’ that had continually been associated with the public’s perception of the Hong Kong Police since the 1970s. The protests pulled the police back to the escalated force in protest policing which in turn led to further declines in perceptions of police legitimacy across the population of the special administrative region. The findings also provide the platform for further conceptual debate on police legitimacy. Copyright © 2020 The Author(s).