The knife used by the accused in the horrific Shahbad Dairy murder was bought by him around 15 days ago from Haridwar in Uttarakhand and police are yet to recover it, a senior officer said on Tuesday.
The accused had planned the murder two days ago after the 16-year-old girl rebuffed him in front of her friends and refused to mend her relationship with him, police said.
On Sunday afternoon, Sahil got drunk and confronted Sakshi, who was on her way to the birthday party of her friend's kid after changing clothes in a public convenience, police said.
She was stabbed several times and later hit on the head by a stone slab, they said.
After killing her, Sahil went to a nearby park and sat there for a while.
Later, he went to Rithala Metro Station where he claimed, he threw the knife in the bushes and headed for Anand Vihar bus terminal from where he took a bus for Bulandshahr in UP.