The Commission reached Lahore on 30 October 1928. The protest march was lead by Lala Lajpat Rai. As the members of commission got down from the train at Lahore Railway Station. The protesters began yelling 'Simon Go Back', soon the protest turned violent and the police had to resort to lathi charge to stop the protest. The SP of Lahore James A. Scott began to beat Lalaji with a baton. Lalaji became wounded from the batoning but he continued to yell 'Simon Go Back...Simon Go Back...Simon Go Back...' Lalaji was wounded and he fell to the ground, before he fell he is said to have announced:
18 days later, Lalaji succumbed to his wounds. Bhagat Singh who was also in the protest march was the witness to this incident and decided to take revenge.
To avenge this, Bhagat made a plan by calling a meeting at Mozang House (an HSRA hideout). On the night, of 10 December the plan to kill the SP Scott was made. Jaigopal was asked to keep a watch on Scott for five days and report the time to fix for execution of plan.
On 15 December, the last meeting was held in which Sukhdev presented a map of the Police Headquarters of Lahore where Scott used to work. Bhagat and Rajguru were chosen to execute the plan. Jaigopal was told to signal Bhagat and Rajguru as he sees Scott coming out of the office. The plan was now ready to be executed.
On 17 December, Bhagat along with Rajguru & Chandrashekhar Azad went to the area of Police Headquarters. Bhagat and Rajguru hid behind a tree nearby. Jaigopal also came riding on his bicycle and acted as he was repairing it to wait for Scott. On 16:20 as another police officer ASP Saunders came out of the office Jaigopal mistook him for Scott and signaled Bhagat and Rajguru. As soon as Saunders approached the tree near the office Rajguru came out and shot him in the head which wounded him and Bhagat shot thrice in his chest and killed him.
The Head Constable Chanan Singh chased Bhagat Singh, Rajguru and Azad but was wounded by Azad's covering fire.
The traffic inspector Fern who was standing there controlling the traffic saw them running and started chasing them. Bhagat fired at Fern but he ducked down to prevent the shot and thus the shot missed. The four then escaped through the D.A.V college backdoor to arranged safehouses.
Next day, Posters appeared all over the walls of Lahore informing the public about the revenge action against the British-
The rest of the matter of the poster contained the motives behind the murder of the officer and warning given to the Intelligence Department and Bureaucracy. It was signed by Balraj (a pseudonym of Chandrashekhar Azad).
When the news of Saunder's murder reached the British government in Lahore. The government launched a search operation in the whole of Lahore. The CID was asked to keep a watch on every person departing and arriving in Lahore.
On 18 and 19 December many people were arrested on suspicion of the murder. Many people were beated mercilessly and caught and jailed without warrant.
The HSRA decided that it is not safe for Bhagat to be in Lahore as he would be soon caught by the police if so. So they planned Bhagat's escape from Lahore to reach Calcutta.
On the evening of 19 December Sukhdev requested Durga Bhabhi (wife of Bhagwati Vohra, member of HSRA) to accompny Bhagat to escape from Lahore. Durga Bhabhi agreed willingly.
To avoid recognition Bhagat had shaved his beard and cut his long hair (a violation of Sikh customs) and had wore an English outfit. He asked Durga Bhabhi to wear an English outfit too. Rajguru was asked to become the porter at the station.
At about 6:00 am Bhagat along with Durga Bhabhi and Rajguru who acted as their porter reached the Railway Station and boarded the first train from Lahore to Calcutta. Chandra Shekhar Azad too escaped Lahore along with them.
In Calcutta, Bhagat and Chandra Shekhar Azad met Jatindranath Das, a scholar and a scientist in January 1929. Jatin was asked to make bombs, arsenals and other weapons for the HSRA. The HSRA set up a bomb factory in Agra for the purpose. In March, the arsenals were tried and tested in secret near the Yamuna River.
In April, the British Government introduced two bills called as Public Safety Bill and Trade Dispute Bill. The first was for the purpose of curbing mass protests that were taking place in many parts of the country and the second was for lowering the pension of the mill workers and farmers by 10%.
Meanwhile, the Bombay Textile Mill workers announced a strike on 15 February to protest against low wages paid by the owner of the mill. The workers remained on strike for many days. They also barred the entry of the owner in the mill. The owner reported the problem to his friend who was a British Officer. The Officer agreed to help him. On 1 April, the Officer came with a large cavalry force to disperse the protesting workers to make way for the owner. First the Officer requested the workers to end the strike but they refused to do so. The Officer then ordered the cavalry to Lathi charge on the workers. Many were injured in this Lathi Charge.
To put a stop on the strikes of workers, the government decided to pass the bills as soon as possible.
The British decided to pass the bills on 8 April.
Bhagat Singh decided to protect the rights of the farmers of his country to protest against unjust laws of the government and decided to halt the passing of bills.
He made a plan to bomb the Central Legislative Assembly in Delhi. He partnered with Batukeshwar Dutt for this task.
On 8 April, as the Speaker Vithalbhai Patel stood up to announce the passing of bill, He bombarded the assembly with two bombs making sure that this will not harm any person. They were shouting slogans of revolution and threw pamphlets.
After the bombarding, they surrendered. He was kept in Delhi Central Jail from 16 April to 13 June.
The trial for Delhi Assembly Bomb case began on 7 May with an introductory hearing with the Presiding Judge Justice PB Pool. In the next hearing, a month later on 6 June lawyer Asaf Ali defended Bhagat Singh and Batukeshwar Dutt. Asaf tried his best to defend the revolutionaries but in vain as on 12 June, both were sentenced to transportation for life in Delhi Jail.
In the Court hearings, Bhagat Singh and Batukeshwar Dutt made a statement to clarify their motives for bombing and about the repressive action of government against the Labourers and Farmers of the country who have a large participation in the economical development of the country. The typewriter had written the whole statement. Here is a small part of the statement.
The next day, the police came to know about his involvement in the murder of ASP Saunders and soon made preparations to transfer him to Mianwali Jail and Dutt to Lahore Central Jail.
The police then took Bhagat and Batukeshwar Dutt to Mianwali & Lahore.
The next day, Bhagat reached Mianwali Jail. He was kept in this jail while all other HSRA revolutionaries were kept in Lahore Central Jail.
The next day, as Bhagat got to know that the English prisoners and thieves were treated with dignity and were given healthy food but there was discrimination with Indian prisoners and revolutionaries and given non-hygenic food as well.
Bhagat began his longest (112 days) hunger strike in jail which lasted from 15 June to 5 October 1929. Together many other revolutionaries began hunger strike that day.
The demands that Bhagat placed before the jailor were-
1. There should be no discrimination between the British and Indian prisoners.
2. Indian prisoners should be given books and newspapers to read and clean clothes to wear as given to the British.
3. Healthy food should be provided to the Indian prisoners.
The demands were refused many times by the jail authorities and the jailors forced the prisoners to break their hunger strike treacherously.
They would often beat the prisoners to drink milk or swallow food to halt the hunger strike but the prisoners were adamant.