[Velveeta]

That mop bucket has always given me pause. Never have I *filled* a bucket to wash a floor. How about you? If Laci was bringing in groceries, then she was certainly able to *partially* fill a bucket to wash a floor. But then, I don't believe that she actually washed it to begin with...

[Devil_Anse]

Perhaps he was thinking in terms of fingerprints on the bucket--his fingerprints might be superimposed over Laci's, since he had been the last one to touch the bucket. And he may have wanted to explain that away even b/f the question was asked... ?