The knife used by the youth in the horrific Shahbad Dairy murder was bought by him around 15 days ago from Haridwar in Uttarakhand and was dumped near Rithala Metro Station after the killing, a senior officer said on Tuesday.

Police are still looking for the knife, they said. 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 their relationship, police said. Sahil, 20, stabbed Sakshi over 20 times and then bludgeoned her with a cement slab, which killed her on the spot. She was found to have 34 injury marks and her skull smashed. His last name is still unknown.