Gangster Atiq Ahmed and his brother, flanked by several policemen, were interacting with reporters when a hand appeared out of nowhere and shot the two in the head in Uttar Pradesh. The men, who were handcuffed, collapsed right there, showed a video from the scene.
The men were being taken for a hospital check-up when they were attacked.
The murder, that was caught on camera, comes just days after Atiq Ahmed's son was killed in a police encounter.
The three killers were immediately overpowered and caught by the police after they shot Ahmed and his brother, said cops.
Chief Minister Yogi Adityanath has constituted a three-member judicial commission to investigate the matter.
A former politician, about 100 cases, including kidnapping and murder, were filed against Atiq Ahmed.
A police team from Uttar Pradesh brought Ahmed, who was in the high-security Sabarmati Central Jail in Gujarat's Ahmedabad, to Prayagraj on March 26 to produce him in a court in the 2006 Umesh Pal kidnapping case.
On March 28, the court sentenced Ahmed and two others to life imprisonment in the kidnapping case.
Ahmed moved the Supreme Court for protection, claiming that he and his family have been falsely implicated in the Umesh Pal murder case and he may be killed in a fake encounter by the Uttar Pradesh Police.