Out hiking in Carey park in Jaffrey, I came upon several of these brightly colored beetles at a mouse carcass. They were quite busy, often running out from under the mouse and taking little loops around and back to it - the carcass moved quite a lot when they went under, and I think the twigs on top had been recently placed there by the beetles.

I think they are Tomentose Burying Beetle (Nicrophorus tomentosus). Jaffrey, NH, 2016/08/28.