According to an exhaustive testimony of Wang released by state-run Xinhua earlier, Bo started intimidating him once he started investigating Gu's role in the case.
This is the first time in the entire episode of Heywood murder case, which rocked the party ahead of this year's leadership change, Bo's name obliquely figured.
Bo, 62, a charismatic leader was sacked from all post and currently facing disciplinary investigations.
Now that Wang's trial is over Bo is expected to go on trial.
After slapping Wang, Bo has removed him as police chief and launched investigations against three other officials who worked with him on the case.
Fearing for his life, Wang said he took the extraordinary step of defecting to the US mission in Chengdu where he stayed for over 33 hours, Wang said.
His testimony says that on Feb 6, under the pretext of discussing business, Wang entered the US Consulate without permission on the pretext of engaging in foreign trade issues or diplomatic issues and later sought asylum, according to the charges filed against him.
Besides the complicity in the murder, Wang was charged with defection, corruption and misuse of power.
While charging him with all these offences, prosecution however sought lenient sentence for him stating that it was due to his efforts that Gu's involvement has come to the light and he cooperated with investigators in unravelling the case.
Image: Former Chinese police chief Wang Lijun attends a court hearing in Chengdu in this still image taken from video September 18 | Photograph: Reuters