A preliminary probe into the killing of a minor girl in northwest Delhi's Shahbad Dairy revealed that the accused was enraged after his break-up with the victim and the fight between them a day earlier triggered the horrific act, police said on Monday.

The accused, Sahil (20), was arrested from Bulandshahr after a call from his aunt to his father was traced to a location in Uttar Pradesh, they said.

A senior police officer said the accused suspected the victim of having an affair with her ex-boyfriend and had allegedly threatened her a few days ago that he would kill her.

"Initial probe also revealed that Sahil had suspicion that she had started talking to her former boyfriend and got into a relationship with him. He had also apparently threatened to kill her," he said.

Sahil brutally killed the 16-year-old girl Sunday evening by stabbing her over 20 times and bludgeoning her to death with a cement slab.

In all, the girl, Sakshi, was found to have 34 injury marks on her body and her skull was ruptured. The final autopsy report is awaited, police said.

"During investigation, police checked the CCTV footage of the area and spoke to the victim's family who said she was going around with a boy named Sahil. We reached his place and the boy was found absconding. Technical surveillance was mounted. We questioned his relatives and worked on all technical aspects.

"A phone by his aunt (bua) to his father informing him about Sahil's sudden arrival helped police to nab him from Bulandshahr in Uttar Pradesh. His medical examination was conducted and by Monday night, he will reach Delhi, following which police will further interrogate him," a senior police officer said.

The accused had switched off his mobile phone after the incident and headed for his aunt's house in Bulandshahr in a bus, police said.

Another police officer, part of the investigation, said when Sahil was questioned about his relationship with the victim, he said he was with her since June 2021.

According to the police, there was a delay of about 25 minutes in informing the police about the incident. None of the bystanders made a PCR call and it was a police informer who alerted the police about the incident, following which a police team was rushed to the spot around 9.30 pm.

Police said the victim had told her parents that she had been staying with one of her friends, Neetu, who has two children and lives in one-room set, police said. Sakshi was staying with her friend for the past 15 days.

The girl had stopped talking to Sahil a few days ago, and had had a fight with him a day before she was killed, they said.

"The girl was in relationship with Sahil since 2021, but of late they often fought over things and shared a strained relationship. She eventually stopped talking to him and wanted to end her relationship with him, but he kept approaching her and wanted to reunite with her," the officer said.

"... Even on Saturday, they had a fight which further worsened their relation. This could be the reason behind the murder," he said.

Police are also trying to know more about a tattoo the victim had on her hand bearing the name "Praveen" which they say could also be a cause of frequent fights between Sahil and the girl and her eventual killing.

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