with an asbestos baffle between
Why asbestos, and not some other flame-retardant material that isn't incredibly dangerous?
a group of █ counties
You've got a lot of these blackboxes throughout the article and they all seem unnecessary to me. They are far more distracting than just including the actual numbers would be.
white-collar employment
You use this term a few times throughout the article and it feels very non-clinical. I'd replace it with something else more specific.
In all cases, the humanoids register ordinary heat signatures, though they do not manifest where any kind of camera, including infra-red, are currently recording.
This seems like unnecessary and leading information. You're telling me something isn't the case when I had no reason to believe it was or wasn't either way. Specifically pointing out something isn't interesting or relevant in this way just feels like a very poor way of foreshadowing something.
display mutually murderous characteristics
This doesn't seem very clinical. I'd just say they display behaviour consistent with the -A instances.
In certain rare cases, individuals not matching the profile will be compelled to join the group, invariably resulting in [DATA EXPUNGED].
Data-expunging like this just feels kind of lazy. Like, you want to imply something big or interesting happened but didn't want to actually work out what it was. If you know what happens here, you should just write it. If not, I'd consider dropping this line entirely.
will preferentially dismantle these bystanders before turning on each other.
Dismantle isn't the right word here. I'd go with "skin", "flay", "mutilate" or something along those lines.
Manifestations in which all subjects expire
You shouldn't use the word "subjects" to refer to anomalous instances; subjects generally has the specific meaning of external actors being used in tests. Say "instances" (or, specifically, "instances of SCP-3402-A") instead.
(0128) Dr. Volk: If you will not co-operate, you will be terminated. Your sentence is only suspended while you are of use to the Foundation.
Eeeeh, this is a very old-school view of the Foundation, where they just callously murder people without thought for not doing what they are told. Obviously there is no canon and you are free to characterise the Foundation as you like, but this line irked me.
//At just before 0300 hours
You're missing the closing italics tags here.