Their was a murder at McDonalds?

A young man was murdered in the McDonalds bathroom, help solve the mystery. Their are six suspects: 1. Steff, the obese girl with acne working the drive thru, 2. Red, the abnormally pale and unnaturally tall ginger, 3. Stephan, the sauve lady's man who lives with his grandparents, 4. Chico, the cook, 5. Ethal, the overly arrogant and obviously to old manager, 6. The guy who mops the floor and doesn't evan work there, Who do you think did it?