appearance of various decorations on uniforms caused this explanation to be doubted. The court ruled in November 2020 that the police had breached the Hong Kong Bill of Rights Ordinance by hiding or not displaying their identification number. In late 2019 the government introduced "call signs" to replace warrant cards, but it was found that officers shared call signs. The police have also repeatedly interfered with the justice process. They have been suspected of tampering with evidence, giving false testimony before court, and coercing false confessions from arrestees. The deployment of undercover officers who were suspected of committing arson and vandalism also generated controversy, and the ability of police officers to identify the differences between ordinary protesters and undercover officers was questioned. A police officer was arrested in April 2020 for perverting the course of justice after he allegedly instructed a teen to throw petrol bombs at a police station he works at. Some uniformed officers used foul language to harass and humiliate protesters and journalists and provoked protesters. The slur "cockroach"—whose dehumanising qualities have been recognised in the social sciences and psychology—was used frequently by frontline officers to insult protesters; some officers sought to counter this development, and suggested that in several instances, verbal abuse by protesters may have led officers to use the term. An officer was reprimanded by his superiors for shouting derisive comments to protesters about the death of Chow Tsz-lok. Police described a man wearing a yellow vest who was taken to an alley, surrounded by police officers, and apparently physically abused by one of them, as a "yellow object". Police were also accused of spreading a climate of fear by conducting hospital arrests, attacking protesters while undercover, arresting people arbitrarily, targeting youngsters, banning requests for demonstrations, and arresting high-profile activists and lawmakers. During the pandemic period, it has also used the law banning groups of 4 to further ban peaceful protests. However, the police were accused of applying double standards by showing leniency towards violent counter-protesters. It has also failed to fulfill its duty to protect the protesters. Their slow response and inaction during the Yuen Long attack sparked accusations they had colluded with the attackers. Lack of accountability Police modified the Police General Orders by removing the sentence "officers will be accountable for their own actions" ahead of the 1 October 2019 confrontation. Police sources of the Washington Post have said that a