Now this is very important people, it is a tactic used over and over again by line managers. You may get called into the office randomly and there are other Sgts in the room, at this point ask if this is an official meeting. Regardless of the response state that you don't feel comfortable and request your fed rep be present. They CAN NOT SAY NO!!! But they may try to say you can have a police friend (colleague) instead. YOU CAN REJECT THIS, and demand your fed rep.
The famous words "Nothing too griefy mate". You should know by now that it most definitely be griefy if not damn right terrible. if the DPS approach you can say this phrase or anything along the lines just know its an issue. I must remind you to never speak to the DPS without speaking to your fed rep first.
So it may not always be diary car, you maybe made tot he same shift with the same person that isnt the most popular. Or whenever the constant watch happens its you thats being sent. You can normally tell when youre being targeted and this is a good sign. If this starts happening you may need to think about leaving that team.
So this is a tactic of the DPS, as you may no they will try and circumvent your fed rep by emailing you directly or your line manager. As dodgy as it sounds its not against any rules, they use our ignorance against us, for the love of everything good DO NOT COMMUNICATE until speaking with fed rep.