Disclaimer: The characters in this story are the property of Dick Wolfe and NBC.
"There!", Munch said empathically pointing to the screen. "There it is again! Rewind the tape!"
"I think my partner's finally lost it." Fin said dryly but did as he was told.
"Stop!", Munch exclaimed. "Right there!"
"What are we looking at, John?", Cragen asked as he joined the group around the monitor.
"Watch the woman in the hat on camera 3.", Munch instructed as Fin slowed the tape down. "Watch when she walks out of range of this camera…"
Elliot, Cragen, and Fin did as they were told. The woman in the hat walked down the hallway. Her presence was recorded by camera 3 until she was out of range and was subsequently picked up by camera 4.
"I don't get it.", Elliot announced as the image of the woman moved off the screen.
"Rewind it again, Fin." Munch demanded.
"John, maybe you could clue the rest of us onto your revelation here…", Cragen instructed.
"There's a blind spot right… there!", Munch exclaimed pointing to the screen.
"Okay…", Fin began, "I'm still not following… camera 4 picks her up again…"
"But look at the umbrella in her hand!", Munch said clearly getting frustrating. "Rewind it again. The umbrella is in her left hand on camera 3 and then it switches to her right hand on camera 4."
"He's right! Look!", Elliot said.
"From the times on these cameras there's a two second gap between where the subject falls out of range for camera 3 and is picked up again by camera 4. Two seconds isn't enough time for her to seamlessly switch hands without either camera picking it up.", Munch explained.
"The recording times on the cameras are off…", Cragen said incredulously.
"Not only that," Elliot continued picking up on Cragen's thought, "but there's a larger blind spot than two seconds…"
Fin jumped in. "Say this isn't the only blind spot in the precinct… if the perp knew where the blind spots where he could walk through this precinct virtually unnoticed…"
"It makes sense in theory", Elliot began, "but our guy only shows up on one camera. One out of almost 30. That means he comes into the building and is picked up by camera 1. Then sometime later he changes into jeans and a sweatshirt. Then follows a long continuous path of blind spots to where Casey is attacked and back until he exits the building past camera 1 again. … there can't possibly be THAT many blind spots in this building. And even if they are how would our perp know exactly where they were?"
Everyone paused for a minute staring at the screen.
"Because he set the cameras himself…", Munch replied slowly. "Our guy sits in his office all day watching us on these cameras… or probably more accurately watching women on these cameras. One day he notices the blind spot. Maybe it starts off as a game. He sees if he can get from point A to point B while appearing on the fewest cameras possible. Then he starts adjusting the cameras and the times. It's not noticeable to anyone else because most people walk in a straight line past all the cameras. Suddenly our little video voyeur has managed to make himself invisible."
"Well I'll be dammed…", Cragen replied. "Good work, Munch. I want the three of you down to that security office now and I want anyone with access to that office and those cameras in interrogation now."
"You got it, Cap", Munch replied as the three detectives hurried for the door.