And so you watch your staff as described, and you see said person put something into their pocket, say, what do you do then?

Ask them, politely, to take it out or empty their pockets,

They say NO,

What do you do then?

You cant touch them, because thats assault.

And YOU dont believe in searching them so,

What do you do?

You can of course call the police, but they would search them.......but you dont believe in that........ do you?