Regarding the bullets at the end of the press release:
This doc is really too long to cut and paste here. The essence of it is that the young man hates all humanity. There are no references to either Anonymous or Scientology. It DOES allude to Darwin.
This entry tells us that Jake Brahm was somewhat active with 4/chan and /b/ but does not mention Anonymous or Scientology. The "threat" was made on /b/. It would appear that Scientology can't tell the difference between the two groups.
Well they might have had some rationale for pulling this one out. The second link is to a blog that connects 4/chan, /b/, and Anonymous although it also states that this was the work of a single individual and not a group.
Yet more reason to believe that you can trust a Scn press release as far as you can throw a Scientologist.