Young Detective - Take 2

A person suspects a single mastermind behind recent attacks. They believe that the attacker of City Hall is the prime suspect as similar markings were found at other locations. The attacks were previously low priority, but the City Hall attack changed that. The person believes that finding who left a certain clue can lead them to the mastermind. However, they discover that their friend is wearing a government official seal and accuse them of being involved. Did anyone see you come up here? Shh! Don't answer that. I've had a break in the case. Listen, you know how I've suspected there is a single mastermind behind all the recent attacks? I think whoever attacked City Hall is our suspect. The same markings showed up at the docks and the mill. All this time, they've kept their business to the north. Low priority. The attack on City Hall changes things. They've gone too far and they know it. If I can figure out who left this, it can lead me directly to whoever's behind it all. The answer is here, staring me in the face. I can feel it. Wait. What are you wearing? That's a government official seal. Why do you... You're one of them now, aren't you? Just like my parents. How could you? Get out!