Believe it or not, it is possible to sue a ham sandwich in the United States — as long as you are the government, and you are bringing a unique type of case called an “asset forfeiture” action.
In an asset forfeiture case, the government sues an item rather than a person, alleging that the item is an asset that a person used in the course of committing a crime and must therefore be forfeited to the government. This type of claim is easier for the government to win than a criminal case. A criminal case requires proof beyond reasonable doubt, while a civil asset forfeiture action uses the lower “preponderance of the evidence” standard.
So if the government had reason to believe that a miscreant ham sandwich was involved in a crime, there’s no reason why we should not read one day about the case captioned United States v. One Ham Sandwich.
Image Credit: Fmarkmanson.net
Adam Nyhan has given the correct answer.
I would only add that there’s a famous saying about grand juries, that an adept prosecutor can persuade a grand jury “to indict a ham sandwich.” Having said that, since a ham sandwich has no independent agency of its own, it cannot be guilty of any crime, and thus this saying is a figure of speech, not meant to be taken literally.