New here, but have been lurking for a while....
Anyway, I was a soldier for 13 years. I was in PSYOP for about 6 years, which is the training the the boyfriend was going through. Although the training is at the JFK Spec Warfare Center and School, it has nothing to do with Special Forces. It is it's own entity, and is not a special forces MOS (military occupation specialty).
Robin Sage is a Special Forces activity, and again, has nothing to do with PSYOP. Sometimes some soldiers were detailed out to provide security or role playing parts in Robin Sage, but it has nothing to do with PSYOP training. Or at least it didn't when I was there.
Because this boyfriend of Megan Touma is an Engineer has no bearing on PSYOP training, and has no connection to the SF Engineer course, which has been posted on here. Many times, soldiers change jobs (reclassify) as a reenlistment incentive. PSYOP has had traditionally high promotion rates over the years, and bonuses for reclass people and reenlistees. This makes it very attractive for soldiers in other specialties to want to do it. It is a relatively small career field, and most of the active duty soldiers are trained and stationed at Ft. Bragg. That means fewer moves over a career, which does get tiring. (There are many reserve PSYOP units all over the country, however).
The field of PSYOP has alot to do with winning the hearts and minds of the enemy without firing a shot in combat, and in peacetime. It really doesn't make someone a Zodiac copycat. When I went through the course, and worked the job, I found it to be alot like advertising. We would do "campaigns" to change peoples minds about things (not in the US, as that is illegal), such as telling farmers that growing carrots is much more profitable than growing coca, telling kids that they should be drug free, etc. This is all done to further US interests in foreign nations. It is done is direct cooperation with foreign governments.
There is no explosives training, other than the usual markmanship training that the military provides. There really is no sneaky pete type stuff going on with it either. The name, Psychological Operations, kind of implies that though.
I am really hoping they find the killer of this young girl. It saddens me that this could happen to anyone, let alone a soldier in the US Army. I just wanted to post this stuff about PSYOP to clear up any confusion there might be about this boyfriend's or POI's (if it is not the boyfriend) chosen career field.