What are the police doing at my neighbor's house?

I was "working from home" today and minding my own business when I heard a police siren nearby. That's odd since my neighborhood is pretty quiet. I look out the window and see a bunch of police pointing weapons towards my neighbor's driveway. I wonder what's up?

Whatever precipitated it, they called an awful lot of squad cars in (at least nine). And a firetruck and ambulance as well. The police stood around my neighbor's truck with weapons pointed while they negotiated with him. Scary. I hope everything ended well.