CORONA, WI—Homeowner and father of three Robert LaFontaine issued a statement late Monday, expressing unease and distrust toward an unfamiliar green 1995 Ford Taurus parked for several hours across from his family's house. "Well, that's different," said LaFontaine, from his post behind the sheer curtains of his living-room window. "Are those out-of-state plates? No, guess not. Can't tell if anyone's in it from here, either. Funny." LaFontaine, while reading the newspaper, continued intermittent surveillance of the vehicle throughout the evening by periodically dispatching eldest son Jack to look out the window.