Answer Happy

There is a three-storey hotel. There are king and double rooms on the second and third levels. A well-known guest enters the hotel and approaches the front desk clerk, who is busy settling a meal order in the hotel's adjacent restaurant. The guest yells at the front desk for not paying attention to her. Then, all of a sudden, the lights go out. When the lights come back on, the famous guest is dead. Other persons in the vicinity include a public attendant cleaning the corner with a chemical, a bellboy transporting a fragile item on the cart, the chef holding a pastry roller, and another guest who is slightly intoxicated. Who is the most suspect and is most likely the one that killed the well-known guest? Explain your answer.