On Thursday, Hong Kong authorities charged pro-democracy activist Ken Tsang with resisting arrest during last year's protests in reaction to China's reversal on a promise to hold free elections in the city in 2017. But in an odd twist of events, they also charged the seven police officers who were caught on video kicking and punching him during the largely peaceful protests, which occupied stretches of city ground over the course of more than two months.

The violent beating of the unarmed, handcuffed activist a year ago today shocked the public when it was first covered by local media.

[RT] [AT]tomgrundy: Images of beating victim Ken Tsang, a Civic Party activist. #occupyHK pic.twitter.com/vpdzCC8Zux — Ai WeiWei (english) (@aiww_en) October 15, 2014

In the video, seven plainclothes officers can be seen carrying Tsang through the streets before taking him to a darkened corner by a building in a public park. Several officers then begin beating the activist while others stand watch. At one point, one of the officers casually takes a sip of water as his colleagues huddle around Tsang. Authorities allege that Tsang had earlier splashed liquid from a bottle on officers as they tried detaining him.

The officers are set to appear in court on Monday, charged jointly with one count of causing grievous bodily harm. One of them was also faces a charge of common assault, police said in a statement.

Meanwhile, Tsang was charged on Thursday with assaulting an officer and four counts of resisting police, according to Hong Kong's Department of Justice. Shortly before he entered the police station, Tsang told reporters that the charges against him were a "kind of political pressure."

"Very simply, the purpose is to make the plaintiff become the defendant," he said, in order to draw attention away from the abuse committed by the officers.

Full public statement from Ken Tsang, a social worker beaten by police on video today — Joanna Chiu ??? (@joannachiu)October 15, 2014

The beating was not an isolated incidence of police brutality. Throughout the demonstrations, known as the Occupy Central protests or the Umbrella Revolution, several videos emerged of police beating activists with batons as they fought to keep protesters away from government buildings or clear makeshift encampments that had been erected in key parts of the city's financial district. Open umbrellas became an unofficial symbol of the resistance, as students used them as shields to repel the officers' batons and tear gas sprayed onto the crowds comprised of thousands of protesters.

Hong Kong has been under Chinese control since 1997, when it was handed over from Britain after 150 years of colonial rule. The student-led protest movement began in late September after China proposed electoral reforms that would allow a direct vote in 2017 for Hong Kong's leader — known as the chief executive — on the condition that all candidates for the post would be pre-screened and approved by a pro-Beijing nominating committee.

At the moment, a 1200-person electoral college selects the city's chief executive.

China had initially promised Hong Kong residents wide-ranging electoral freedom after it was handed back to the mainland under a formula of "one country, two systems," but the agreement was not explicitly legislated.

Despite prolonged protests and intense media coverage, the demonstrators' demands for universal suffrage have yet to be realized. In June, Hong Kong legislators failed to approve the China-backed electoral reforms, which pro-democracy activists have labeled a "sham."