After committing the crime, the accused had fled to his native place in Etah in Uttar Pradesh, the police said.
On June 7, the unidentified body of a man was found in the Vasant Kunj area. The man was later identified as Kishan Karki from Nepal who was murdered by Harbir Singh Pal following a heated argument over a petty issue.
"Since the incident pointed fingers at the standard of policing, all resources of the district were pressed into action," said Devendra Arya, Deputy Commissioner of Police (DCP), south-west district.
During investigation, the police recovered empty liquor bottles from near the murder spot. On scanning the CCTV footages of the nearby wine shop, the police spotted the deceased with another person.
The police then circulated the photographs of the two persons on WhatsApp besides putting them up at various prominent locations which finally resulted in identifying the deceased after Kishan's cousin approached the police on seeing the photographs.
"On August 7, a police team at the said wine shop spotted and apprehended the suspect who was seen with Kishan in the CCTV footage," Arya said.
During interrogation, the accused confessed to killing Kishan. He revealed that while he was consuming alcohol on the night of the incident, Kishan, who was unknown to him, requested him to give him some liquor. He then took Kishan to the wine shop and purchased alcohol.
"The two then went to a lonely spot behind the ILBS Hospital in Vasant Kunj. While they were drinking, a heated argument broke out between the two following which the accused hit Kishan on the head with stones which resulted in his death," the DCP said.
( With inputs from IANS )