I'm finishing up the third edition of my First Amendment and Related Statutes textbook, and for it I wrote up a brief summary of the libel law rule when a speaker (e.g., a newspaper, a blogger, a book author, and the like) accurately reports someone else's statement, which turns out to be false and defamatory. Since people had asked me about this in the past, I thought I'd blog my summary here.
Assume that blogger Alan writes, "Betty alleges Charlie committed armed robbery." Alan's statement is literally true: Betty did make the allegation. But the statement Alan is reporting on (Betty's statement) is false, and Alan has the mental state that would make him culpable if he were the original accuser (for instance, he entertained serious doubts about the truth of Betty's allegation, which is enough to make him liable under a recklessness theory, even if Charlie is a public figure).
a. The general "republication rule" is that a speaker is responsible for the factual assertions in others' statements (assuming the speaker has the constitutionally required mental state), even when he expressly attributes the statements to others. The truth or falsity of Alan's statement is evaluated as to the allegation that it repeats (Betty's report), and not only as to the assertion it literally makes (that Betty reported it). Restatement (Second) of Torts § 578.
And this is true even if Alan distances himself from the allegation, for instance by saying that Charlie has denied the statement, or that Betty has reason to lie. The principle is that "Tale bearers are as bad as tale makers."
b. Some recent cases disagree, and evaluate the statement's truth based on whether the allegation had indeed been made, not based on whether the allegation (which the statement reports) is true. See, e.g., KTRK Television v. Felder, 950 S.W.2d 100 (Tex. App. 1997); In re United Press Int'l, 106 Bankr. 323 (D.D.C. 1989). This, though, is a minority view; the view mentioned in (a) remains dominant.
c. But say that a reporter is covering a trial, in which witnesses are making assertions that the reporter knows are false, or knows are likely false; or say a reporter is reporting on some official government report. The law has long recognized that such speech must in some measure be immune from liability, even when under the general rule (see 6.a above) the reporter's speech would be actionable. Under the common-law fair report privilege, the reporter and the newspaper are protected against liability for evenhanded and substantially accurate reports of government proceedings. In many states, this is an absolute privilege, applicable even when the reporter knows that the statements within those proceedings are false (or are likely to be false).
In the other states, though, this privilege is merely a "qualified" privilege, which means that it can be lost when the reporter is acting with "actual malice." Such a qualified privilege still offers some protection, for instance when the statements are about a private figure and would thus be actionable if said negligently -- the reporter would then get the benefit of the "actual malice" test under the qualified privilege, rather than just the negligence test that would be applicable without the privilege. But if the reporter knows the statement in the government proceeding is false (or is reckless about the possibility), he and his employer can be held liable. The Supreme Court has never decided whether an absolute fair report privilege is constitutionally mandated.
d. What if the statement is outside a government proceeding? Consider this incident, from Norton v. Glenn, 860 A.2d 48 (Pa. 2004): "[City councilman Glenn] claimed that [council president Norton] and [city mayor] Wolfe were homosexuals and ... strongly impli[ied] that Glenn considered Norton and Wolfe to be ‘queers and child molesters.' ... Glenn [also] asserted that Nortion had made homosexual advances toward Glenn which escalated to Norton grabbing Glenn's penis ...." A newspaper published an article accurately describing the charges, and quoting Norton's unequivocal denial; the newspaper didn't adopt or concur in Glenn's statements. Norton and Wolfe sued both the newspaper and Glenn. The jury in the lawsuit against Glenn found that the statements were false.
e. Some courts would hold that the newspaper would nonetheless be protected under a First Amendment "neutral reportage" privilege, because the charges themselves were newsworthy even if they were false. (Why might that be?) "[W]hen a responsible, prominent organization ... makes serious charges against a public figure, the First Amendment protects the accurate and disinterested reporting of those charges," even when the reporter has serious doubts about the accuracy of the charges. Edwards v. National Audubon Soc'y, 556 F.2d 113 (2d Cir. 1977). Some later cases have extended this to certain charges on matters of public concern against private figures, and to statements made not just by responsible, prominent organizations but by any public figure, or even by any nonanonymous source.
f. Other courts, however, have rejected the neutral reportage privilege. In Norton v. Glenn, for instance, the Pennsylvania Supreme Court held that Norton's and Wolfe's lawsuit against the paper could go forward, and the paper could be held liable if it published Glenn's statements knowing of a high probability they were false. The case eventually settled for an undisclosed amount.