Kerala Police had on Wednesday increased the security cover given to Mavelikkara Additional Sessions Judge-I, V G Sreedevi, after taking serious note of the online threats made against her.
A senior police official told PTI that one person was arrested and two are under custody and their details will be revealed soon as the investigation is still on.
The court had on Tuesday sentenced 15 people associated with the now-banned outfit Popular Front of India (PFI) to death in connection with the 2021 murder of the BJP OBC wing leader that took place in Alappuzha district.
Soon after, posts on social media platforms verbally insulting the judge cropped up and were circulated by various accounts.
In the order, the court said there was "absolute justification" in giving capital punishment to all the accused persons in this case.
Sreenivasan, a lawyer and the BJP OBC Morcha state secretary, was brutally attacked and killed in his home on December 19, 2021, in front of his family, by activists affiliated with PFI and the Social Democratic Party of India (SDPI).
Police at the time said they suspected that the murder was in retaliation for the killing of SDPI leader K S Shan just hours earlier. The trial in Shan's murder case has not yet begun.