Pu was arrested by the Chinese police in May 2014, ostensibly for having "caused a disturbance." The arrest followed Pu's attendance at a meeting of dissidents who were campaigning for official recognition of the Tiananmen Square protests of 1989. Four other lawyers who attended the event were also jailed. The prosecution examined his personal history, notes and computers, and interrogated his associates, but failed to find any evidence of treason, sexual misconduct, or corruption. The only evidence provided by the prosecution consisted of provocative blog posts. He remained in custody despite the courts having rejecting the case for lack of evidence.