"Miskin was also the hitman in the murder of Kannada journalist Gauri Lankesh at her residence in Bengaluru on September 5, 2017," SIT said in a release quoting from the chargesheet filed on Saturday.
The six other accused are Amol Kale, Praveen Prakash Chatur, Vasudev Bhagavan Suryavamshi, Sharad Kalaskar and Amith Ramchandra Baddi,
Kalburgi, 77, was shot dead by unidentified assailants from a close range when he opened the main door of his house in the city's Kalyan nagar suburb on August 30, 2015.
Kalburgi, a rationalist, was a former Hampi University vice-chancellor at Hospet in the state's northwest Ballari district.
"The accused were allegedly inspired by a book 'Kshatra Dharma Sadhana' brought out by the Hindu extremist group Sanatan Sanstha," said the charge-sheet.
Interrogation of the accused revealed that they conspired to eliminate Kalburgi after he delivered an address on a topic titled "Towards a superstition free society", a debate on the enactment of the Karnataka Prevention of Superstitious Practices Bill, 2013, at Vigyan Bhavan in Bengaluru on June 9, 2014.
Based on his speech, the accused depicted Kalburgi as a 'durjan' (devil incarnate), as mentioned in Kshatra Dharma Sadhana.
"The accused jointly hatched a conspiracy to murder Kalburgi in furtherance of the achievement of their goals and executed it," the SIT said.
To execute the plan, the accused also stole a motorbike, did recce of the victim's house and the locality, practiced shooting at a village in Dakshina Kannada district on the state's west coast.
"Chatur and Miskin rode on the stolen bike to Kalburgi's house on August 30, 2015 around 8.30 a.m. and knocked on the main door. As he opened the door, Miskin shot him twice on his forehead and vanished from the scene on the same bike," said the charge-sheet.
( With inputs from IANS )