"If you're a doctor, you should know the dangers involved."

He knows the people involved and has a deeper knowledge of the situation.

Sorry Don caught one, but we all know the risks involved.

I know the risks involved, but he should be trained.

Each also knew the dangers involved, but they didn't dwell on that.

Unlike Honor, he did know the people involved, and something had to be done.

But people who know the groups involved say that hasn't happened.

In some cases you know the people involved and can form a view about their reliability.

In fact, somebody who didn't know the two men involved would have said they were both working themselves into a foul temper.

But I can clearly understand, knowing the people involved, how it happened.