The girl, whose family lives in a roadside shanty along LJ Road, had gone missing early Thursday morning. Her body was found in the same area a few hours later.
After questioning several suspects, the police zeroed in on Mehadi Hassan (23) as the culprit, said the official.
Hassan, who lives on the pavement, abducted the girl when her parents were asleep, took her to a nearby secluded place and sexually assaulted her, the official said.
He then allegedly strangulated her and left the body there, the official added.
The accused was arrested under kidnapping, rape and murder under the IPC as well as under the Protection of Children from Sexual Offences Act.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)