Katju wrote a letter congratulating Chavan on "your strong step in suspending the police officers who arrested the girl who put up an item on Facebook objecting to the shutdown in Mumbai on the death of Bal Thackeray, as well as the girl who supported her".
He said that the Supreme Court and high courts have "repeatedly held that such bandhs and shutdowns are illegal as they paralyse the entire civic life" in the city.
"Hence what the girls did was in accordance with the Supreme Court judgement. How then could their act be called illegal? In fact it was the policemen who arrested the girls who acted illegally and committed the criminal offences mentioned in sections 341 and 342 IPC," Katju wrote.
Earlier on November 19, he had raised his voice against the arrest of the two girls in Palghar near Mumbai and sought action against the cops who carried out their arrests.
In his letter, he said that if a policeman is issued an illegal order by his superior (whether political or police) it is his duty to refuse to carry out such illegal order, otherwise he must be charged for a criminal offence and given harsh punishment.
The former Supreme Court judge said that if a policeman is given an order by a superior to commit murder, dacoity or rape, he must not obey.
"It seems to me that the delinquent police officers who ordered the arrest of Shaheen and the other girl, and those who implemented this illegal order, succumbed to the pressure of the hundreds of hooligans who came to the police station. What kind of policemen are these who succumb to hooligans," Katju asked.
"I am informed that in recent years hooligan gangs have flourished in Mumbai and other parts of Maharashtra, and they have terrorised people living in the state. Some of them profess a separatist ideology," he said.
"In my opinion these should be crushed with an iron hand, and it is your duty, as the chief minister to do this, as Chanakya has advised in the Arthashastra, and Bheeshma Pitamah in his upadesh to Yudhishthir in the Shantiparva of Mahabharat," he added.