Do I match the description of a serial killer? If I do, then perhaps a visit to my house is warranted. And if I'm a serial killer, and, depending on the method of killing, perhaps they have to believe that I'm armed to the teeth. Coming to pick me up could be dangerous for them. Now, their measured response involves an unannounced SWAT.

I don't see "Serial Killer" levels of scrutiny in this story. I see the right amount of scrutiny, but with a precursor of a cop getting his gun hand ready in a situation that doesn't call for it.