The banned Communist Party of India-Maoist (CPI-Maoist) Saturday owned responsibility for killing former minister and Janata Dal-United (JD-U) legislator Ramesh Singh Munda.
A press statement from the CPI-Maoist said the legislator was "deceiving the people of the state and has been punished".
The leftist guerrilla outfit also expressed grief over the death of a student in the firing incident July 9, when Munda was shot dead during a prize distribution function at a school in Bundu, in the outskirts of the Jharkhand capital.
The outfit has apologised to the family members of the slain student. Munda's two security guards were also killed in the firing.
The police have detained the principal of the school, Umesh Chandra Gyani, for questioning.
The Jharkhand government has announced a Central Bureau of Investigation (CBI) probe in the killing of Munda.