Noun
a crime so serious that capital punishment is considered appropriate
Source: WordNetCertain types of loudmouthism should be a capital offense among decent people. Robert A. Heinlein
Don't kid yourself, knowing too much is a capital offense. In politics it always has been. Robert A. Heinlein
There's a group in California that wants to make suicide a capital offense punishable by death. That's like punishing somebody for being on a hunger strike by sending them to bed with no supper. Bill Engvall