Rajguru was born at Khed, near Pune, in what was then British India. He was a member of the Hindustan Socialist Republican Association, who wanted India to be freed from British rule by any means necessary. He believed that ferocity against oppression was far more effective against British rule than the nonviolent civil disobedience preferred by Mahatma Gandhi.
Rajguru became a colleague of Bhagat Singh and Sukhdev, and took part in the assassination of a British police officer, J. P. Saunders, at Lahore in 1928. Their actions were to avenge the death of Lala Lajpat Rai who had died a fortnight after being hit by police while on a march protesting the Simon Commission. The feeling was that Rai’s death resulted from the police action, although he had addressed a meeting later.
The three men and 21 other co-conspirators were tried under the provisions of a regulation that was introduced in 1930 specifically for that purpose. All three were convicted of the charges and hanged on 23 March 1931. They were cremated at Hussainiwala at the banks of the Sutlej river in the Ferozepur district of Punjab.