One day a detective investigates a case where a dead man was found in the kitchen of his house. Police reason that this was an act of suicide, judging that he had pills in his mouth. The detective opens the refrigerator and finds some lettuce, a chopped tomato, a marinating steak, a slice of cheddar cheese, and a half-drunken water bottle. The detective was like "Of course this is a murder!"
What was the detective's reasoning?