Extra security at Croton-Harmon

Snapped these 3 pictures this evening.
I haven't seen this kind of security outside Grand Central until now. Has anyone else?
This morning, I could swear I saw one of them out in the yard.
I wonder if there was some sort of specific threat.

It looks like the MTA increased security at all of its facilities today. NYPD and National Guard forces were deployed at Jamaica on the LIRR. I noticed more police in the subways too. It's weird because now you are seeing more and more detectives in uniform.

I don't think there is a specific threat. If there is a particular threat directed at the transit system, the MTA has upped their presence system-wide as a response.

Nester

National Guard was guarding the entrance to High Bridge Yard tonight, and the day before as well. I was told by having the Guard on the facilities, MTA PD is available to patrol the trains easier...

weren't you a bit nervous taking those pictures?

I don't see any reason to be nervous. If they had asked me to stop taking pictures, I would have stopped.
(Plus I did it discreetly, so as to not attract attention! )

The military is watching ALL of the rail yards on the property including an observation post at Woodlawn Jct.