No. (i) In this example, peace and calm are inappropriate adjectives. The converse might be strife and mayhem, and the gang did not cause strife and mayhem, they cause personal insecurity. (ii) As it is reported speech, the commissioner's words would be in the past perfect.
"The commissioner said that the riots had now ended and that peace and calm had finally returned to the city."
"The commissioner said that with the arrest of the criminal gang, the city was finally a safe place to be." (Less likely: "personal safety had finally returned to the city.")