Ranjit Singh Rana and Sewa Singh after breaking the iron rods of their cell were on way towards the inner boundary wall of the prison when they were caught by the staff, Deputy Superintendent Central Jail, Balkar Singh Bhullar, said.
Rana was arrested for allegedly murdering Assistant Sub Inspector (ASI) Ravinder Pal Singh while on duty on December 5, 2012.
According to the complaint, Rana teased Singh's daughter and passed lewd comments.
After an argument, Rana allegedly shot dead the ASI from a close range. At the time of incident, Rana was District urban Secretary of ruling party SAD.
Sewa Singh was arrested under NDPS Act. A case has been registered against the two for attempting to escape from the prison, sources said.