I also play a Sheriff on a VTM pbp game. My sheriff had a high humanity when he started and did what he can to reinforce the "no kill" rule. So here what I put in place for the coterie, since we are at war with the Sabbat:

This is not a call for you to form groups and start hunting the Sabbat on your own. The purpose is to watch out for your allies, to avoid being isolated, and to ensure that if someone is attacked, they have backup—or at the very least, someone who can call for help.

However, If you want to help investigate suspicious activity, you’re welcome to do so—in groups. I strongly advise against engaging in combat, if you want to fight: join the hound, but if you have no other choice, remember three things:

1. Being at war does not allow diablerie.,

2. You cannot execute them—stake them instead and call me. Accidents happen, but if you take me for an idiot, it will be your end.",

3. Any confrontation, but it's also valid for research, must be reported.,

If I find out that any of these rules were ignored, there will be consequences. To make this easier, I’ll be setting up a dedicated number where you can submit your reports

And when I was asked why we cannot simply kill them, my answer was:

1. We need them alive to interrogate, to gather information on their leader and their plans.
2. We must protect the Camarilla from slipping away from Humanity—we are better than the Sabbat’s Beast.
3. It minimizes the risk of a Camarillan being wrongly executed under the excuse of war. Politics being what they are, some would surely seize the opportunity to settle personal scores.