The crowd also pushed off a policeman from the same balcony when he had gone to save the person, Superintendent of Police Sudhir Kumar Porika said.
Six journalists were injured in the violence in Mahalpar area.
The incident, a video of which has gone viral on social media, took place when the accused was hiding in a house after gunning down a 28-year-old man identified as Diwakar Kumar and was captured by the local people, the SP said.
They beat him up and threw him off the first-floor balcony of the house injuring him seriously.
One policeman who tried to rescue the accused was pushed off the balcony too and he was also injured, he said.
The mob ransacked the house and set fire to at least six vehicles.
Altogether 11 policemen including two deputy SP level officers were injured in a clash with locals who indulged in stone pelting, the SP said.
Nine persons were arrested in this connection, Porika said adding that heavy police force have been deployed in the area.
The situation is under control now, he added.