Mehzabin Islam Moon, who had been arrested in a case filed over the murder of her parents and younger sister in the capital's Kadamtali area, has confessed to the crime.
Dhaka Metropolitan Magistrate Begum Yeasmin Ara recorded her confessional statement on Thursday and ordered to send her to jail.
Earlier, investigation officer Zakir Hossain produced her before the court after completion of her four-day remand and urged the court to record her statement as she agreed to give so.
Mehzabin's uncle Shakhwat Hossain lodged the case with Kadamtali Police Station against her and her husband Shafiqul Islam.
Earlier on Saturday morning, police recovered the bodies of a couple and their daughter from their house at Kadamtali Muradpur. They were Mehzabin's parents - Masud Rana, 50, and mother Moushumi Akter, 45 - and younger sister Zannatul, 20.
The police station sub-inspector Abul Kalam Azad had told Jago News that she herself informed police through 999 in that morning saying, "I have killed parents and sister. You come and detain me."
The sources said Mehzabin came to her father's home two days before the killing and complained to her mother that her husband Shafiqul and sister Zannatul developed an extra-marital affair.
An altercation occurred over the matter that might lead her to conduct the murder, the sources added.
JA/SU