Gangster Sanjeev Jeeva was shot at inside the Lucknow Civil Court on Thursday.
According to the police officials, the assailant made his way to the court disguised as a lawyer.
The gangster was accused in the murder of BJP leader Brahm Dutt Dwivedi and was brought to court for a hearing.
Jeeva collapsed at the spot after being shot at while a police officer also sustained injuries.
DCP West and DCP Central reached the court premises after receiving word of the incident, said Assistant Commissioner of Police Sunil Kumar Mishra.
Further details are awaited.
This report is filed by ANI news service.