Okay, here's the thing with the police...you can use actual lethal force against them...or you can find other options.
I'll lay them out a bit -- you can disrupt them, spoof them or just outright engage them. There are weapons, obviously, and the Vigil also has EMP weaponry available to it. And there is data warfare. Odds are if they aren't hacked into police communications, they can be in pretty short order.
Your call on how to handle it, there will be consequences to that decision. Remember, the Vigil is covert, or at least it was covert, and this tactical decision will affect the organization's profile.