The year 1928 was marked by an anti-Simon Commision upsurge everywhere in India. On 30 October 1928, the Simon Commission faced a large hostile crowd led by Lala Lajpat Rai at Lahore Station. The Lala was severely beaten by the Police under J. A. Scot, British SP and he later succumbed to his head injury.
The whole nation was stunned by this savagery. As news of the attack on Lajpat Rai spread, the country reacted with anger.
Bhagat Singh was appalled. He could not believe that a white man could dare take a stick in hand and set upon Lajpat Rai. The HSRA (Hindustan Socialist Republic Army) decided to undertake retaliatory action. On 17 December, Bhagat Singh, Rajguru, Sukhdev and Chandra Shekhar Azad mistook the ASP, J.P.Scot for Saunders, as they pounced upon him and shot him dead.
A few months later, on 8 April 1929, Bhagat Singh and Batukeswar Datta threw a bomb in the Central Legislative Assembly Hall in Delhi. It was hurled from the midst of a packed gallery, not aimed at anybody, but to draw the attention of the House, the Indian people and the British rulers in India.
As Bhagat Singh and Batukeswar Dutt had planned not to escape after throwing the bomb, they were arrested. While Dutt was sentenced to transportation for life in the Assembly Bomb Case, Bhagat Singh, alongwith Rajguru and Sukhdev, was sentenced to death for the murder of Saunders in what became famous as the Lahore conspiracy case.
While in jail, Bhagat Singh took up the cause of bettering jail conditions and commenced a hunger strike. The Jail Committee requested Bhagat Singh and B.K. Dutt to give up their hunger strike but they declined. As the fast continued indefinitely with no solution in sight, Jawaharlal Nehru visited Bhagat Singh and the other hunger strikers in jail.