What began as a peaceful sit-in near Hong Kong's political centre on June 21, 2019, gradually escalated as hundreds of people moved to police headquarters. The demonstrators demanded that police retract their use of the term "riot" to describe clashes on June 12 between anti-extradition bill protesters and police. They also called for rioting charges to be dropped against fellow protesters who were arrested on that day. Despite a plea from police inside the building for the group to leave,…