The police have arrested nine persons who had allegedly beaten up and tied ASI Nirjit Singh to a pole yesterday. They have been booked for attempt to murder besides other sections of the IPC.An inquiry by SSP Daljinder Singh Dhillon revealed that the ASI was not responsible for helping the accused tractor trolley driver Gurdev Ram flee from the crime scene after killing Sarbjot Singh in Gokhuwal village.Ram revealed that he had escaped nearly an hour before the ASI reached the spot. At 3 am today, two SPs, 4 DSPs and half a dozen SHOs reached at a pre-determined point near Gokhuwal village. As many as 150 cops were also requisitioned from nearby police stations. All routes to the area were sealed and nobody was allowed to move out.By 6 am, based on inputs provided to them by CID personnel, the cops had identified and nabbed 12 people and whisked them away to the Civil Lines police station. Three of them were let off after preliminary investigations revealed that they had no major role to play in the incident.Although no senior officer was willing to go on record yet sources claim that the irate cops vent their anger by thrashing the accused at the police station.A case under Sections 307 (attempt to murder), 353 (assault or criminal force to deter public servant from discharge of his duty), 486 (selling goods marked with a counterfeit property mark), 435 (mischief by fire or explosive substance with intent to cause damage), and the National Highway Act has been registered against them.Meanwhile, DGP Suresh Arora announced a reward of Rs 5000 for the ASI apart from a commendation certificate.