Answer :
I conclude that the sheriffs attitude is that of boredom and wants to get out of there or that the sheriff is hiding something and being very guiltless. If that makes any sense.
In this passage, we learn that the sheriff has already looked at everything that is to be found in the house, and that he believes there is nothing that could point to a motive for the murder. However, we learn that he thinks kitchen things are unimportant. This shows that the sheriff is not very inquisitive, as he does not think of the possibility of "kitchen things" being used for murder.