The actor plays an intense threat assessment detective on the hit U.S. show and now he fears he knows too much about stalkers and their targets.

He tells U.S. news show Access Hollywood Live, "I've installed cameras at my house and you can watch the day back to see if anybody came to your property... I sit there and watch a lot of video."

Fortunately, MCDermott has only seen his gardener and the mailman on video.