Conversation so far:
What politics was Sri into?
This sparked an outburst of public anger against the British, leading to civil unrest and a nationalist campaign by groups of revolutionaries, who included Aurobindo.
What other revolutionaries got involved?
In 1908, Khudiram Bose and Prafulla Chaki attempted to kill Magistrate Kingsford, a judge known for handing down particularly severe sentences against nationalists.

Question: What stopped them?
Self-contained rewrite: What stopped Khudiram Bose and Prafulla Chaki from killing Magistrate Kingsford?