ARA, Dec. 27 -- The mystery surrounding the murder of Jharkhand Police constable (havildar) Pashupati Nath Tiwari has been unravelled, officials said. Police said the murder was committed at Bhagwatpur village, under the jurisdiction of Chandi police station, on December 20. The constable was allegedly murdered by his son, who was addicted to drugs, along with a friend, in an attempt to secure a job on compassionate grounds. To destroy evidence, the accused allegedly threw the sharp weapon used in the murder and other items, including a blood-stained jacket, into the Sone River. Both the accused were arrested on the basis of technical evidence, police said. The arrested persons have been identified as Vishal Kumar Tiwari, the constable's only son, and Mohammad Zeeshan Ahmed Jilani, a resident of Hazaribagh. Jilani was arrested from Hazaribagh, while Vishal was apprehended from his native village. Police said Jilani, a resident of Lekh Road, Noora, under the Losingna police station area of Hazaribagh, and Vishal had been close friends for over 15 years. A mobile phone used in the crime has also been recovered. During interrogation, both the accused allegedly confessed to the crime. Sub-Divisional Police Officer (SDPO), Sadar, Ranjit Kumar Singh said that constable Pashupati Nath Tiwari, who was posted at the Hazaribagh Police Control Room (PCR), had recently come to his village with his wife. On the night of December 20, while he was asleep at home, his throat was slit with a sharp weapon. Following the incident, Bhojpur Superintendent of Police (SP) Raj ordered a detailed probe. The SDPO said that during questioning, both the accused admitted to drug addiction. According to Jilani, the constable was unhappy with his son's drug habit and frequently reprimanded him. Police further said that the constable had recently finalised an agreement to purchase about two bighas of land in the village, a fact he had not shared with his son. Vishal allegedly became furious, suspecting that his father would invest his entire retirement money in the land. Investigators said Vishal then plotted to kill his father so that he could secure a job on compassionate grounds and escape his father's constant scolding and reprimands. The SDPO said Jilani works as a welder and also delivers parcels in his spare time. Vishal allegedly told Jilani that drugs were available cheaply in Aurangabad. On the evening of December 19, the two left Hazaribagh but instead of going to Aurangabad, they went directly to Bhagwatpur village. At around 1.30 am on December 20, they allegedly entered the house through the back door and slit Pashupati Nath Tiwari's throat while he was asleep. Police said Vishal also allegedly cut off his father's thumb to prevent fingerprint identification. After committing the crime, the duo allegedly returned to Hazaribagh on a motorcycle the same night. The murder weapon and other items were later thrown into the Sone River from Sahar bridge. Based on the statement of the constable's wife, a First Information Report (FIR) had earlier been registered against unknown assailants....