Question

What might the leaders of the committee of public safety have said to justify this law

Answer 1

Hello!

The justification to the comittee of public safety was the guarantee of the conquered rights with the revolution. 
Hugs!

Answer 2

Referring to the law of suspect

I believe the answer is: It is for the freedom of the people and to protect them for the enemies. Also, this change is only for the better and we need this in our lives.

The law of suspect gave the government the power to capture and examine the people who are challenging their view.
Even though they say to the people that the purpose of the law was to protect the citizens, the european governments use this law to prosecute the protesters that deemed as problematic for the governments.