The structure of this sentence escapes me. Is this a form we have seen before? Is there a sort of passive verb going on here?
bị for bad things and dược for good/neutral are used to form passive, right
I am confused too, seems to be the wrong way round.
"Ai ̣đã bị bắt giữ bởi cảnh sát vào hôm qua' is also accepted.