One of the accused in the killing of Assistant Sub-Inspector (ASI) Harjit Singh was shot dead in an exchange of fire with the police in the Islamabad area here on Saturday night. Hunt is one for the second suspect in the case.The deceased was identified as Deepak Singh, a resident of Mulechak village. The police said Deepak was identified as one of the suspects during the investigation into the killing of the ASI.Harjit Singh was shot dead while on duty near the Bhagtanwala grain market under the Gate Hakima police station on Thursday night. He suffered a bullet injury on the back of his neck and died on the spot.According to the police, CCTV footage, technical inputs, tower-dump analysis and information from local sources helped investigators establish the identities and movement of the suspects.The police said a team signalled two suspects travelling on a scooter to stop at a naka around 9.45 pm on Saturday. The suspects allegedly opened fire at the police party and fled towards another checkpoint.The police said the suspects again opened fire when they encountered the subsequent naka, firing four rounds. Police personnel retaliated in self-defence, leading to an exchange of fire in the Islamabad police station area.Deepak sustained gunshot injuries. He was rushed to a hospital, where he later succumbed to his injuries.The police claimed to have seized a .30-bore pistol, two magazines containing eight live cartridges, a mobile phone and an Activa scooter allegedly used in the crime.The killing had triggered a major police operation in the city. Multiple teams had been scanning CCTV footage to trace the route taken by the suspects after the shooting. Preliminary investigation suggested that two Sikh men were seen fleeing on a scooter from the Bhagtanwala grain market around 12.32 am.Director General of Police Gaurav Yadav, who visited Amritsar on Friday, said specialised teams had been constituted to crack the case.Meanwhile, Harjit Singh was cremated with state honours at his native Rampur Bhutwind village on Saturday after his daughter arrived from England. ADGP (Law and Order) AS Rai and Amritsar Police Commissioner Harmanbir Singh Gill attended the cremation.