A security guard..
June 17, 1972.
Frank Wills was on a night shift one day, when something curious struck his eye. He was in the Watergate office building in Washington, DC., and he had saw a piece of duct tape on the lock of a basement door, to keep it from latching shut. He had thought someone, like a worker, had left it there by mistake, so he removed it. Around 30 minutes later he had discovered the lock covered again. He rushed to the lobby telephone and requested the Second Precinct police.