Tripathi is under trial for murdering his first wife Suman in 2003 and was out on bail. He killed Suman when she found about his affair with Firoza who then lived in Khadra.
Tripathi on being arrested told police he was aware of the illicit activities of Saira Bano and had warned Firoza to stay away from her. He thought his wife had obeyed his command, but was surprised to find that she was still in contact with Saira Bano. He scolded Firoza and even broke her cell phone.
That very moment Tripathi decided to eliminate Saira to save his wife and daughter from her clutches.
On June 1, Tripathi called his aide Amir and explained him his plan. He went to Saira's residence and presented Amir as a customer. While talking to Saira, Tripathi quickly observed what jewellery Saira was wearing and shot her with a countrymade pistol. While he was pulling out her gold rings and earrings and bangles, her younger sister Soni who lived on the first floor came downstairs and witnessed the crime. When she tried to run away Amir caught her from behind and Tripathi shot her too. They left the house and fled on the bike.
Thanks To:
http://timesofindia.indiatimes.com/city/lucknow/Madiaon-double-murder-case-solved-killer-held/articleshow/48351892.cms