The Uttar Pradesh government had in November handed over the probe to CB-CID.
Chief Judicial Magistrate Gopal Tiwari issued the warrants against Anil Balyan, Vikas alias Guddu and Shah Nazer.
Tyagi was gunned down in the courtroom during a hearing in another case here on February 16, 2015. Shooter Sagar Malik was arrested from the spot while Brijbir Singh was nabbed the next day.
A court has already framed charges against Sagar, Brijbir and Saeed Mulla while five others are absconding.