The Delhi Police on Wednesday recreated the scene of crime in northwest Delhi's Shahbad Dairy, where 20-year-old Sahil allegedly killed a 16-year-old girl, even as the investigators are yet to find the murder weapon three days after the incident, officials said.
Police have also recorded the statements of three friends of the victim.
Fresh CCTV footage has emerged in which the victim is seen walking on a street minutes before she was killed.
The Bharatiya Janata Party (BJP) has demanded death penalty for the accused and alleged that the killing was a fallout of 'love jihad'.
Police said Sahil was taken to the spot in the early hours of Wednesday.
"Due to security concerns, Sahil was taken to the spot in the early hours of Wednesday. We recreated the scene of the crime to establish the sequence of events and understand how he executed the crime and what did he do after that," a senior police officer said.
Sahil allegedly threw away the knife he used to kill Sakshi into the bushes at Rithala. The knife is yet to be recovered, the officer said.
According to police, three of Sakshi's friends -- Bhawna, Ajay alias Jhabru and Neetu -- were called to join the investigation and their statements have been recorded.
Deputy Commissioner of Police (Outer North) Ravi Kumar Singh said, "We have the accused in our custody and his interrogation is underway. We are looking at all aspects to connect the links. We are working to unearth the role of all the individuals involved in the incident. Our teams are trying to recover the weapon used in the crime."
A senior police officer said during interrogation, Sahil said he was angry after Sakshi rebuffed him in front of her friends and refused to get back to him.
The probe carried out so far has revealed that no one was involved with Sahil in the crime, police said, adding that the accused has confessed to have executed it himself.
He has also told police about the location in the forest area of Rithala where he threw the murder weapon but since it was dark on Sunday night, he has not been able to point out the exact spot.
The friends of the victim who were questioned have been cooperative, police said, adding that they have revealed how despite Sakshi telling Sahil sternly that she did not want to continue in a relationship with him and to stay away from her, the accused kept following her.
Police are likely to seek further custody of the accused for at least five days.
Locals took out a candle march demanding strict punishment for the accused. Around 150 to 200 people took part in the march, which was taken out in a market area near the victim's residence.
Ajay told police that Sakshi had complained to him about Sahil on Saturday.
He told PTI Video, "On Saturday, Sakshi said Sahil was pestering her. Me, along with Bhawna and Sakshi, went to meet Sahil and asked him not to bother her. However, on Sunday, he committed the crime."
"When I heard about the incident and went to the spot, I saw her body lying there. Her skull was ruptured and her intestines jutting out. I helped the police shift the body into an ambulance," he added.
BJP MP Manoj Tiwari said, "The killer in the Shahbad Dairy murder case should be hanged as soon as possible. A special team should be formed to deal with such cases under the supervision of the lieutenant governor so that the (Arvind) Kejriwal government's appeasement policy does not affect court trials."
Delhi BJP chief Virendra Sachdeva said fast-track courts should be set up and special prosecutors appointed for cases of rape, murder or 'love jihad' as there is already tremendous pressure on the regular prosecutors.
'Love jihad' is a term often used by BJP leaders and right-wing activists to allege a ploy by Muslim men to lure Hindu women into religious conversion through marriage.
Tiwari also alleged that the killing was an outcome of "love jihad" and said it is necessary to find out whether any organisation is working to promote such incidents.
Sakshi was stabbed more than 20 times and then bludgeoned with a cement slab, killing her on the spot. Her body had 34 injury marks and the skull was smashed.
Sahil had allegedly hatched the plan to kill Sakshi two days before the incident.
Sakshi had rebuffed him in front of her friends and refused to mend their relationship.
Police had earlier said Sahil got drunk on Sunday afternoon and in the evening, confronted Sakshi, who was on her way to the birthday party of her friend's child after changing her clothes in a public convenience.
After killing Sakshi, Sahil went to a nearby park and sat there for a while.
Subsequently, he went to the Rithala metro station where he claimed to have thrown the knife into the bushes. He then took a bus from the Anand Vihar ISBT to go to Bulandshahr in Uttar Pradesh, police said.
A call to his home led to his arrest from Bulandshahr.
