Riya Begum alias Moina, 27, was arrested in a raid in the Satarkul neighbourhood on Thursday night, according to Rafiqul Islam, chief of Badda Police Station.
Renu, a 42-year-old mother of two from Mohakhali in the capital, was beaten and killed by a mob on July 20. Police have so far arrested 14 people, including Moina, in connection with the lynching.
The woman, who was living at Mohakhali with her 11-year-old son and 4-year-old daughter, went to the school to inquire about admission. Guardians took her to the headmaster’s room for questioning on suspicion that she was an abductor.
Angry locals, who gathered outside on hearing that “a child abductor has been caught”, later snatched her away and lynched her. Police responded immediately but the woman died before they arrived.
Renu is among at least six people killed recently following rumours that “child abductors are on the prowl to collect heads and blood for construction of Padma Bridge” spread on social media, especially Facebook.