On 16 April 2021, detained human rights lawyer Chang Weiping's family received a written notice from the Baoji Municipal Public Security Bureau to say that the human rights defender was formally arrested on 7 April 2021 on the charge of "subversion of State power". Prior to the formal arrest, Chang Weiping was detained under "residential surveillance in a designated location" (RSDL) for the lesser charge of "inciting subversion of State power". Under China's Criminal Law, those convicted of "subverting State power" may face a maximum sentence of life imprisonment.

Under the Criminal Procedure Law, the Baoji public security authorities must complete their investigation within two months and then make a decision whether to recommend prosecution or drop the case. With the approval of a higher-level procuratorate, this investigative period is extendable by up to five months if certain broadly defined conditions are met, such as if the case is deemed to be "particularly serious and complicated".