He came over to where the head of security stood.

"And you're head of security around here, so you know how to use it all."

What had he done now that the head of security was after him?

The head of security came down to meet the old man.

The head of security was too irritated to know or care.

He was also joined by the presidential head of security.

I know that the former head of security is on administrative leave.

The head of security was doing a nice job under the circumstances.

He'd have to let his head of security in on the situation.

That is usually known only to the chief executive and the head of security.