Inside Story of Zhang Yang's Coup and Suicide

On Nov 28, 2017, Chinese government announced that Zhang Yang, the former member of the Central Military Commission and Director of the Political Work Department, hanged death at home 5 days ago. This is the first military tiger hanged death known by public in recent 40 years history of CCP. Chinese government determined the nature of Zhang Yang's suicide was to commit suicide to escape punishment. What crimes in hell had he committed so that he'd rather hanging himself than staying in Qin Cheng Prison? Is this a suicide or a murder? Who else among those senior military figures were involved? What kind of coup plot did they have and were afraid of being exposed? Why he bent down his knees before Xi Jinping and asked for pardon?