The SIT got the first breakthrough six months after the crime.

This year began with scepticism over the probe into the murder of journalist Gauri Lankesh on September 5, 2017, with the special investigation team (SIT) having failed to make any headway even three months after the crime.

However, a breakthrough unravelled the plot behind a series of murders of rationalists and writers, Narendra Dabholkar (2013), Govind Pansare and M.M. Kalburgi (2015) and Gauri Lankesh (2017) in Karnataka and Maharashtra.

The SIT struck gold in February when they picked up K.T. Naveen Kumar from Maddur. The SIT claimed that Kumar had a peripheral role in the Gauri murder, but was actively planning the murder of K.S. Bhagavan, a rationalist based in Mysuru. But the SIT suffered a setback as Kumar's handler, Praveen, was alerted by media reports and went underground, derailing the probe for another three months.

In their pursuit of Praveen, the SIT arrested Amol Kale, Amit Degvekar and Manohar Edave in Davanagere. Kale and Degvekar turned out to be the kingpins of the conspiracy and diaries recovered from them led to a series of arrests in the next three months.

Leads from the SIT probe led to several arrests in Maharashtra and uncovering of a plot to bomb a music concert in Pune.

Significantly, all the missing pieces in the murders of Dabholkar and Govind Pansare fell into place. The CBI and the Maharashtra SIT have now arrested Kale, Degvekar and Rajesh Bangera, all accused in the Gauri Lankesh murder case, for the murders of Dabholkar and Govind Pansare.

The Karnataka CID, probing the murder of Kalburgi, arrested Ganesh Miskin and Amit Baddi, who were part of the hit team that killed Gauri Lankesh, and is all set to arrest Kale, Degvekar and Bangera as well.

The probe has now revealed that a criminal syndicate, mostly made up of people with links to Sanatan Sanstha, was formed in 2011 to kill ‘durjans’, or ‘Hindus who are anti-Hindu’, motivated by Kshatra Dharma Sadhana, a Sanatan Sanstha publication. The syndicate was allegedly led by Dr. Veerendra Tawde, a Pune-based ENT surgeon who oversaw the killings of Dabholkar, Pansare and Kalburgi. Kale was his deputy.

The CBI arrested Dr. Tawde in June 2016 in connection of the murder of Dabholkar.

The probe has now indicated that Kale took over the leadership of the syndicate after the arrest of Dr. Tawde, and led the murder of Gauri Lankesh, and was in the process of planning the murder of Professor Bhagavan at the time of his arrest.

The SIT has alleged that a former editor of Sanatan Prabhat, the mouthpiece of Sanatan Sanstha, funded the syndicate, with Degvekar being the link between the editor and the syndicate.

The Supreme Court, hearing a petition filed by the family of Kalburgi earlier in December, issued a notice to the CBI asking why a central agency must not probe all the four murder cases, as multiple investigations had now indicated that a single conspiracy was behind the murders of the four persons in two States over four years.

The case is expected to come up for hearing in the first week of January 2019.