I noticed this when I first joined the server and it caused a fair bit of confusion for me.
Under 'Mutant':
- Mutants can not kill in Government buildings.
Under 'Server 1 - downtown_v4c':
- Mutants KOS people who attack them first, or anyone who is in the PD, warehouse, spawn tunnels or PD district. These 'zones' stop as soon as the tunnel begins. ( Not including the Mining Area )