In 1928, the British government set up the Commission, headed by Sir John Simon (Later, Lord Simon, 1st Viscount Simon) to report on the political situation in India. The Indian political parties boycotted the Commission, because it did not include a single Indian in its membership, and it met with country-wide protests. When the Commission visited Lahore on 30 October 1928, Lajpat Rai led a non-violent march in protest against it. The protesters chanted "Simon go back" and carried black flags.
He did not fully recover from his injuries and died on 17 November 1928. Doctors thought that Scott's blows had hastened his death. However, when the matter was raised in the British Parliament, the British Government denied any role in Rai's death. Although Bhagat Singh did not witness the event, he vowed to take revenge as it was a murder of a very tall leader in the freedom movement, and joined other revolutionaries, Shivaram Rajguru, Sukhdev Thapar and Chandrashekhar Azad, in a plot to kill Scott to send a message to British Raj. However, in a case of mistaken identity, Bhagat Singh was signalled to shoot on the appearance of John P. Saunders, an Assistant Superintendent of Police. He was shot by Rajguru and Bhagat Singh while leaving the District Police Headquarters in Lahore on 17 December 1928. Chanan Singh, a Head Constable who was chasing them, was fatally injured by Azad's covering fire.