The victim, Srikant Bhardwaj, made two desperate calls to the Bariatu police station and four calls to the officer-in-charge’s mobile phone as his alleged killers cornered him in Swami Sahajanand Colony some time after 5 pm.

Policemen, who had allegedly lost their way, arrived at least half-an-hour after Bhardwaj and his three friends had been brutally beaten. Bhardwaj died of excessive bleeding from wounds to the head later that evening; one of his friends, Om Prakash Pandey, is being treated for multiple injuries at the Rajendra Institute of Medical Sciences (RIMS).

Police said they had arrested one person who appeared to be the “prime accused”, but who could not be named because he was a minor.

“The arrested individual is a minor and he looks like the prime accused. Witnesses could identify only one person, and we are working backwards using that information. We have zeroed in on at least 10 others; there will be arrests soon,” Bariatu station in-charge Phaguni Paswan said.

A resident of Swami Sahajanand Colony — an immigrant hub of under-construction and newly-build brick houses skirting the perimeter wall of RIMS — said four young men had been drinking in an empty plot behind the house of the 29-year-old woman. At some point, they had scaled the wall of the house and asked the woman — the wife of a security guard at a local branch of the State Bank of India — for water. She had obliged, but when the youths came back to ask a second time, she had refused, the resident, who declined to be identified, said.

The refusal allegedly enraged the men who grabbed the woman and dragged her out into the courtyard, abusing her loudly, neighbours said.

Bhardwaj, whose own house is being built diagonally opposite the woman’s and who was witness to the incident, allegedly intervened and chased the men away. Within 15 minutes, however, at least two of the four men returned with about 10 others and attacked Bhardwaj and his friends, police said.

“After lunch at home, my brother left on his bike to see the new house,” Rajnikant, the dead man’s brother, said. The family, including Bhardwaj, his wife and their two young sons, lives in Bariatu Housing Colony nearby. “He told us he would be with friends,” Rajnikant said.

A resident of Swami Sahajanand Colony said, “This is still a sparsely populated locality. That day, most families were out celebrating the New Year. Bhardwaj and his friends were the only ones to react when the woman was attacked. They were good, decent people.”

The resident said it was to be expected that the youths who attacked them, all residents of Tiril Basti, would return with others to extract their revenge.

Police officer Paswan said, “According to information available to us now, at least two from the first group were part of the second. It was all over in five minutes.”

Bhardwaj was cornered in an empty plot overgrown with weeds adjacent to his own. Blood-stained pieces of two pens and dislodged teeth lying on the ground told the story of the assault.