Phones, and then phone records separately probably, vehicles, houses, Google (if applicable), etc.
Not a lot, all things considered. It's early yet though, so I'm not sure we can read much into that.
Usually in cases where murder/suicide is a possibility, we get a leak or sometimes even an official statement that a weapon has been recovered. That's what I'm hoping for here, if we don't get more than that in the meantime.
My suspicion is that the scene may look like a murder/suicide, but based on this guy's history and the devastation that closing the door could cause to a potential murder case, they're being really careful.