I apologize. I will respond in English, because it's easier and I want to make sure that I'm very precise on this.
We came across the police stations when we were tracking how, exactly, Chinese authorities managed to return—according to their own statements—230,000 individuals through clandestine means between April 2021 and July 2022 alone. As we tracked these operations, we came across two jurisdictions in particular, which are the ones mentioned in “110 Overseas”. Together with some chatter among dissidents and activists on social media channels, in looking at these two jurisdictions, we came across statements on the websites of the public security authorities themselves, as well as confirmation of those reports in PRC state and party media.