The boy confessed to the crime and led a police team to the spot where the body was found.
A 17-year-old boy was apprehended for allegedly killing his tuition mate in Shahdara, the police said on Sunday.
A complaint was received on Saturday evening regarding a missing girl, a resident of Naveen Shahdara, a senior police officer said.
Investigations revealed that she had gone to meet some of her friends in the afternoon but did not return till late evening, Meghna Yadav, Deputy Commissioner of Police (Shahdara), said.
Through local enquiry and mobile phone details of the missing girl, her movement and persons whom she was in touch with was established, the DCP said.
Thereafter, it was revealed that she had been in touch with one of her friends following which the boy was called for questioning, said Mr Yadav.
The boy initially said they had gone to an ice-cream parlour together and from there he had returned home, the officer said.
During further interrogation, the boy revealed that he had killed the her, she said.
He told police that he knew her from common tuition classes and recently he got in touch with her and they started meeting frequently, Mr Yadav said.
He confessed to holding a grudge against the victim due to an incident which had happened in their tuition class due to which he was reprimanded, the DCP said.
He had planned to take revenge. When he met the girl on Saturday, he took her to an isolated under construction building next to Welcome Metro Station. He mixed some drugs in her cold drink and she became semi-conscious, Mr Yadav said.
Later, he tied her with the tape and strangulated her and hit her head, said the DCP.
The boy confessed to the crime and led a police team to the spot where the body was found, she said.
Prima facie there does not seem to be any sexual assault, the DCP said.
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