How does criminal libel differ from civil libel?
In criminal libel, the theory is that the damage is to the public rather than to a private individual. Therefore, the state becomes the prosecuting entity against an individual speaker. Presumably, the individual’s libelous statement would have to be deemed serious enough to warrant removing the case from the civil realm. The defamation involved in criminal libel could be of another individual, a public official, a government entity, a group, or even a deceased person.
Didn’t New York Times Co. v. Sullivan eliminate the basis for criminal-libel suits?
No. In Sullivan (1964), as well as in Garrison v. Louisiana the same year, the Supreme Court extended some First Amendment protection to some false statements of fact leveled against public officials and public figures. But it did not find criminal libel unconstitutional.