When Charley stabs Dandridge in the hand with his pencil, he stabs the hand holding him by the neck. The depth of the wound on Dandridge's hand reveals that the pencil should have stabbed Charlie in his neck and given him a severe wound, if not kill him.
This can only be seen for a brief second on the widescreen side of the DVD. In the scene where Dandridge follows Charlie and Amy in Club Radio, there is a man standing by a mirrored column, and Dandridge walks behind him, and for a second you can see Dandridge's shoulder reflected in the mirror. Vampires do not have reflections.