Yashpal Singh, one of the lawyers caught on camera assaulting journalists, JNU students and teachers at the Patiala House Court complex, was arrested by the Delhi Police on Tuesday.
Lawyer Vikram Chauhan has not joined the probe yet.
Earlier, Delhi Police Commissioner B.S. Bassi said that coercive action will be taken against two out of three lawyers.
The police had earlier issued summons to lawyers Vikram Singh Chauhan, Yashpal Singh and Om Sharma to join the investigation, following which Om Sharma presented himself before them and was arrested.
After the other two lawyers did not oblige, the Delhi Police took Yashpal Singh in custody.
