Chow, 23, pleaded guilty last month to incitement and taking part in an unauthorised assembly outside the Wan Chai headquarters on June 21, 2019. Joshua Wong Chi-fung, Chow’s colleague in the now-defunct party Demosisto, was also charged over the incident.

Agnes Chow (right to left), Joshua Wong and Ivan Lam remained defiant ahead of their appearance in court on Wednesday. Photo: Sam Tsang

Chow was formally convicted at West Kowloon Court on Wednesday, after prosecutors read out their case against her in court. Her sentencing was adjourned to December 1, which will be the final day of a six-day trial for Wong and a third defendant, Ivan Lam Long-yin, over the same incident.

The court heard that Chow had provoked a large crowd outside the Legislative Council, there to protest against the now-withdrawn extradition bill, to surround the police facility at 11am that day by chanting “besiege the police headquarters”.

According to the prosecution, she successfully mobilised hundreds of protesters to assemble outside the premises, where they blocked its entrances, removed barriers, pelted the building with eggs, sprayed graffiti, vandalised CCTV cameras and caused serious disruption to nearby traffic.

She was later seen outside the police headquarters chanting slogans and affixing placards containing slogans in support of the demonstrations. The unauthorised assembly ended at about 3.45am the next day, with the number of protesters reaching a peak of 9,000 at 10pm.

Some police services were suspended during the protest, with a total of 61 emergency calls failing to reach officers inside headquarters. Seven officers and eight canteen staff members were sent to hospital after reporting feeling unwell during the siege.

Wong and Lam, aged 23 and 26 respectively, have pleaded not guilty to their charges and will stand trial on November 23.

Wong has denied the same charges to which Chow pleaded guilty, while also pleading not guilty to a third count of organising the public meeting. Lam, the former chairman of Demosisto, also pleaded not guilty to incitement to take part in an unauthorised assembly.

Prosecutors said they would call 17 witnesses to court in support of their allegations and introduce WhatsApp messages seized from the defendants’ phones as evidence. The defence counsel is expected to argue the messages should be disqualified because they were obtained via illegal means.

Before Wednesday’s hearing, Chow said she and her allies would not give up on their fight for freedom and democracy.

“Under this strong sense of fear of the national security law, it is even more important for us Hongkongers to not surrender, and to continue to believe in the universal values of democracy and freedom,” she said.

Wong also said he would remain defiant: “With the political persecution that we face, and under the threat of Beijing, it is not the time for us to surrender.”

Last month, Chow told the press she had made the decision to plead guilty because she believed her clear criminal record could save her from a potentially hefty punishment, adding she was mentally prepared to serve months in prison.

She was arrested in August of last year alongside Wong during a crackdown on student leaders, a district councillor and a pro-independence activist.

Soon after the new national security law took effect on June 30 this year, Wong and Chow revealed their decisions to withdraw from Demosisto, which was subsequently disbanded the same day.