Columnist: The chief of police has claimed in a recent press conference that the decline in the number of pickpockets caught on the street indicates that his department that has partly eliminated this petty crime. He might as well argue that because there are higher levels of fog over L.A., there are fewer stars in the night sky. The gentlemen of our police department, in all likelihood, have caught fewer acts of petty crime lately simply because their vigilance is haphazard, at best.

The columnist's statements, if true, best support which of the following as a conclusion?