Cross reference calendar with clipboard.

That's a good thought. You run back to the back room, grabbing the clipboard - and for good measure, the punch cards - and return to the office, looking over them. Custodial Staff was definitely working today, clocking in at 10 AM and clocking out a few minutes before the murder was reported. You flip back a month, seeing that CS started crossing off dates last month on the fifth. Seems he got hired around then. On the clipboard, Grand Homme has shipments going back for much longer. This also goes into your mental notebook.