Appellants appeal the summary judgment dismissal of their defamation action. We hold that the story that respondents broadcast in the early evening newscast of December 1, 1978 was materially false, and that appellants presented sufficient evidence for a trial on the issue of actual malice. We reverse.
Facts
The background of this case was a racketeering scandal of proportions unprecedented in this state which attracted intensive media attention. On November 28, 1978 the Pierce County Sheriff and seven others were arrested on racketeering charges. In connection with those charges, there was a federal probe into a series of Pierce County arson fires. In addition to those stories, the media reported that a local bail bondsman and one of the persons arrested, Lamont Zemek, had been vacationing earlier that month with a local district court judge and the Prosecuting Attorney of Pierce County, Don Herron. Herron had practiced law in both the public and private sectors since March 1959, until he was elected as Pierce County Prosecuting Attorney in 1975. Before the racketeering scandal, and the news broadcast linking him to that scandal which is the subject of this lawsuit, Herron had never come under scrutiny by the local or Washington State Bar Associations.
Respondent Don McGaffin was a news reporter with KING Broadcasting Company, better known as KING TV Channel 5. On December 1, 1978, McGaffin wrote and broadcast on KING TV a story that is the subject of the instant suit.
*516Sometime in mid to late November 1978, McGaffin had received an anonymous telephone call stating that the Pierce County Prosecutor's Office was under investigation by the FBI for improper bail bond procedures. McGaffin tried to contact Herron, by phone and in person, but was unable to obtain an interview. During a visit to the prosecutor's office he had a brief discussion with Deputy Prosecutor Terry Sebring, who confirmed that the office was under investigation by the FBI regarding bail bond forfeitures. Sebring would not give more information, however, due to the continuing investigation. McGaffin's response was very hostile. Sebring swore in an affidavit as follows:
McGaffin then stepped very close within a foot of me with his face showing of anger and said, "You mean to tell me that you will not talk to me about bailbond procedures even in general?" I replied, "I have given you my statement. The records are public information in the Clerk's Office."
He then said, "what happens after the bench warrant is issue? [sic]" I replied, "You are asking me a question I am not discussing further." He then said with his face close to mine and lowered his voice, "You will regret doing this (indicating refusing to answer his questions). I will get you (could have been 'fix you'). Just watch the news".
Clerk's Papers, at 262-63. McGaffin's hostility was corroborated by witnesses to the scene, reporter Barbara Anderson and receptionist Maria Chantrey, who heard Mc-Gaffin's loud "parting shot": "Watch the (evening) news, Sebring". McGaffin denies any threat or animosity toward Herron.
McGaffin next interviewed the Pierce County Superior Court Clerk, who supplied statistics on bail bond forfeitures collected from local bondsmen. McGaffin also spoke briefly with at least one Pierce County judge about bond forfeitures.
McGaffin contacted former Pierce County Prosecutor Ron Hendry, and one of Hendry's former deputies, Douglas McBroom. In an election characterized as "unusually bit*517ter," Herron had defeated Hendry in 1974. McGaffin claims that they discussed bail bond forfeiture procedures as well as the contributions made by bail bondsmen to Don Her-ron's 1974 campaign, and that one of the two told him that approximately half of Herron's 1974 campaign contributions originated from bail bondsmen.
Neither Hendry nor McBroom believes he made such a statement. Although he remembers a discussion with McGaffin, Hendry cannot specifically recall whether they discussed bail bonds or bail bondsmen's contributions to Herron's campaign. Hendry was certain, however, that he did not tell McGaffin that "approximately half" of Herron's contributions came from bail bond interests because he knew otherwise. Hendry testified in a deposition as follows:
Q. Would you have told Mr. McGaffin that over half the money collected by Mr. Herron in his campaign to defeat you was supplied by the bail bond interests of Pierce County?
A. No.
Q. Would you have said approximately under one-half?
A. No.
Q. Okay, why wouldn't you have used those words?
A. My recollection from the campaign is that the bail bond contributions to Mr. Herron's campaign were in the neighborhood of $1,500.
Q. If Mr. McGaffin would have asked you how much you thought the bail bond interests would have contributed to Mr. Herron's campaign, what would you have told him? $1,500?
A. Yes.
McBroom similarly does not remember the topic of his conversation with McGaffin. Although he testified candidly that he had no specific recollection of whether or not he told McGaffin that Herron had raised a $120,000 campaign fund, he stated, "I certainly don't believe I told him that. I didn't know how much Mr. Herron raised at that point. I don't know if I ever knew how much Mr. Herron raised." Answering a question as to whether he told McGaffin or other reporters that over half or approximately half of Herron's campaign contributions came from bail bond *518interests, McBroom responded similarly: "I don't think that I probably, I'm sure I didn't know."
McGaffin also looked at the Public Disclosure Commission's campaign contribution reports for Herron. The reports list contributors by name, and state the amount contributed next to each name. The reports reveal that the total contributions for Herron's 1974 campaign were approximately $38,000, of which only $825 was contributed by bondsmen. McGaffin could not have determined that approximately half of Herron's campaign contributions came from bail bondsmen from those reports.
McGaffin wrote a story which he read during the 5:30 p.m. newscast on December 1, 1978. It stated:
The Prosecutor's office in Pierce County has ... it has been confirmed that the FBI is being investigated by the Prosecutor's Office in Pierce County [sic]. The FBI agents are questioning the Chief Prosecutor, Don Herron, and his deputies about bail bond procedures. Bondsmen John Carbone and Ron Williams are two of the eight men arrested and charged by the Justice Department on racketeering charges this week. Carbone heavily contributed to Herron's election campaign four years ago and again in 1978. Also arrested for racketeering was Herron's close friend and vacation companion, Lamont Zemek. Zemek's ex-wife, Nina Zemek, is Herron's long-time administrative aide. The FBI wants to know how Herron and the Pierce County Prosecutor's Office collected forfeited bail bonds, particularly from bondsmen Carbone and Williams. That was confirmed for KING-5 News today when Deputy Prosecutor Terry Sebring told me that he could not discuss bail bond matters. He said it would be inappropriate because his department is being questioned by the FBI and other Justice Department officials. This is the way . . . this is what the FBI is looking at. Let's say you get arrested and charged with a felony down in Pierce County. Sources inside the Sheriff's Department told KING-5 News today the jail officials will urge you to call Carbone's bail bonding company. Say bail is set at $10,000. You don't have the $10,000. The bondsman, Carbone, for instance, will put up a bond ... a piece of paper . . . for $10,000. You pay Carbone approximately $1,000 in fees. But if you skip *519town, then what happens? At that point the prosecutor is supposed to file a motion in court demanding that your $10,000 bond be forfeited to the county. The judge signs the order. The prosecutor is then supposed to serve notice on the bail bondsman to produce the $10,000 which then goes into the Pierce County Treasurer's Office. That is what is supposed to happen, but if a prosecutor doesn't push the bail bondsman for forfeiture and he doesn't pay up, what happens? Do the judges know? Or check? No. The Clerk of the Court has no way of knowing. Records are organized in such a way that they can't know. Only the prosecutor knows. A deputy ... or . . . plus a deputy or two. KING-5 News has learned that only 18 times since 1975 has bail been collected on forfeiture in all of Pierce County Superior Court and only 4 of those cases were handled by the Carbone bail bonding company. Once in '75 . . . three times in 1977. Bail bondsmen were irritated at the former Pierce County Prosecutor, Ron Hendry, for pushing to collect those forfeited bail bonds monies. They contributed approximately half of all campaign money collected by Don Herron, who then beat Ron Hendry in 1974.
Clerk's Papers, at 187-88.
The allegations in the story that a bondsman had "heavily contributed" to Herron's campaign in 1974 "and again in 1978," and that bail bondsmen "contributed approximately half of all campaign money collected by Don Herron . . ." are conceded to be false. The innuendo in the story that Herron was involved in the racketeering scandal and was not collecting bond forfeitures because his friends and campaign contributors were bail bondsmen is also false.
The story was rewritten and read again by a different broadcaster on the 11 p.m. newscast that same evening. Although the content was similar, this report included a statement that bail bond interests had contributed "approximately $50,000" to the campaign. KING destroyed the audio tapes of both broadcasts, but retained a video tape copy of the 5:30 p.m. newscast.
A variation of the story was subsequently printed in the December 2,1978 edition of the Bremerton Sun. This story, attributed to McGaffin and obtained from the United Press *520International wire service, indicated that former prosecutor Hendry had an aggressive record of forfeiture enforcement against bail bondsmen, and implied that his 1974 defeat by Herron was linked to Herron's bail bond support. The printed story also stated that "Herron collected a $120,000 campaign chest, about half of it coming from bail bond interests." Clerk's Papers, at 11. The report further stated that Herron's largest single contribution came from Nina Zemek, who was Herron's administrative assistant and former wife of bondsman Lamont Zemek, Herron's friend. United Press International no longer has a record of how it obtained the information which was printed by the Brem-erton Sun.
Herron sued KING Broadcasting, McGaffin, and the Bremerton Sun for defamation. His complaint set forth five specific statements alleged to have been defamatory, all of which appeared in the printed article published by the Bremerton Sun.
After the expiration of the statute of limitation, Herron sought to amend the complaint to add United Press International as a defendant, but the amendment was dismissed as untimely. Herron then sought to amend the complaint to add statements made during the 11 p.m. newscast of December 1, including the statement that bail bond interests had contributed "approximately $50,000." The trial court denied the second requested amendment as untimely, ruling that because each newscast constituted a separate cause of action for defamation, the amendment could not relate back under CR 15(c) to the filing of the original complaint. The court then granted summary judgment in favor of all defendants, holding that Herron failed to make a prima facie showing of actual malice as to the Bremerton Sun, and a prima facie showing of material falsity as to McGaffin and KING Broadcasting. Herron appealed from these orders. The Bremerton Sun was subsequently dismissed from the appeal.
*521Relation Back of Amendment
CR 15(c) allows an amendment to relate back to the date of the original pleading "[w]henever the claim or defense asserted in the amended pleading arose out of the conduct, transaction, or occurrence set forth or attempted to be set forth in the original pleading . . ."An amendment stating a time-barred new cause of action is not allowed where the amendment involves an unrelated event occurring at a different time. Olson v. Roberts & Schaeffer Co., 25 Wn. App. 225, 228, 607 P.2d 319 (1980).
At common law, each publication of a defamatory utterance (e.g., each sale of a book) constituted a separate cause of action. R. Sack, Libel, Slander 91 (1980); see Holden v. American News Co., 52 F. Supp. 24, 32 (E.D. Wash. 1943). Most jurisdictions have now adopted the "single publication rule," which states that any one edition of a book or newspaper, or any one radio or television broadcast, is a single publication. Restatement (Second) of Torts § 577A(3) (1981). We find the single publication rule the better reasoned rule in light of the modern realities of mass publication and broadcasts to wide audiences.
In this case, the amendment sought to add statements made on the 11 p.m. newscast, including the false statement that bail bond interests contributed "approximately $50,000” to Herron's election campaign. The 11 p.m. newscast was the result of a conscious independent act, using a new script and broadcaster, and so clearly constitutes a separate publication, even under the single publication rule. See Libel, Slander, at 92. The amendment does not relate back to the filing of the original complaint because the statements did not arise from the same conduct, transaction or occurrence set forth in the original complaint. CR 15(c). The trial court did not err in denying the amendment. The second broadcast is, however, evidence of KING'S actual malice.
Defamation
A defamation plaintiff must establish four essential ele*522ments: falsity, an unprivileged communication, fault and damages. Mark v. Seattle Times, 96 Wn.2d 473, 486, 635 P.2d 1081 (1981), cert. denied, 457 U.S. 1124 (1982). When the plaintiff is a public official and the allegedly defamatory statement concerns the plaintiff's public duties, the plaintiff must show that the defendant acted with actual malice. New York Times Co. v. Sullivan, 376 U.S. 254, 11 L. Ed. 2d 686, 84 S. Ct. 710, 95 A.L.R.2d 1412 (1964).
In order to overcome a defendant's motion for summary judgment, the public official plaintiff must present a prima facie case with convincing clarity. Anderson v. Liberty Lobby, Inc., 477 U.S. 242, 91 L. Ed. 2d 202, 106 S. Ct. 2505 (1986). Mark, at 487; see also Dunlap v. Wayne, 105 Wn.2d 529, 534, 716 P.2d 842 (1986). Despite this heavy burden, as with ordinary summary judgment motions, the evidence of the nonmovant is to be believed, and all justifiable inferences are to be drawn in its favor. Anderson v. Liberty Lobby, Inc., supra; Herron v. Tribune Pub'g Co., 108 Wn.2d 162, 170, 736 P.2d 249 (1987). Here, it is indisputable that KING'S broadcast was not privileged and that it severely damaged Herron in his professional reputation by associating him with racketeers. This opinion is therefore limited to the issues of material falsity and actual malice.
A
Material Falsity
A defendant in a defamation action may obtain summary judgment by showing that the story's "sting" is true. Mark, at 494. The "sting" is the gist of the story as a whole, and is only altered when "significantly greater opprobrium" attaches to the false statement than it would to the truth. See Mark, at 496. Inaccurate reporting is not defamatory unless by altering the "sting" it creates a materially different impression on the reader.
The trial court characterized the sting of the 5:30 p.m. newscast as: (1) a prosecuting attorney was under investigation concerning bail bond practices; (2) he had a close friend who was arrested with two local bondsmen; and *523(3) he had accepted substantial sums from a bondsman to finance election campaigns. Since the trial court determined that all three of these items were true, it determined that the false statements about bondsmen contributing "approximately half" of Herron's election funds, with one contributing "again in 1978", did not make any appreciable difference in the impact, or "sting", of the broadcast.
Herron assigns error to the trial court's characterization, contending that the true "sting" was to implicate Herron in a criminal conspiracy, giving an overall impression that he bargained away his ethics and integrity in exchange for campaign contributions. We agree. In that context, the statement that "approximately half" of Herron's campaign contributions came from bail bondsmen carries significantly greater opprobrium than the more accurate figure: approximately 2 percent. The false statement thus affected the "sting" of the story itself. Herron has made a sufficient prima facie showing of material falsity to preclude summary judgment.
B
Actual Malice
A public official who sues for defamation may only recover damages upon a showing that the defamatory statement was made with "actual malice" — that is, made with knowledge of its falsity or with reckless disregard of its truth or falsity. New York Times Co. v. Sullivan, supra at 279-80. "Reckless disregard" means (1) a "high degree of awareness of . . . probable falsity", Garrison v. Louisiana, 379 U.S. 64, 74, 13 L. Ed. 2d 125, 85 S. Ct. 209 (1964); or (2) that the defendant "in fact entertained serious doubts" as to the statement's truth, St. Amant v. Thompson, 390 U.S. 727, 731, 20 L. Ed. 2d 262, 88 S. Ct. 1323 (1968); Tilton v. Cowles Pub'g Co., 76 Wn.2d 707, 722, 459 P.2d 8 (1969), cert. denied, 399 U.S. 927 (1970).
The standard for determining "actual malice" is subjective, focusing on the defendant's belief in or attitude toward the truth of the statement, not the defendant's per*524sonal hostility toward the plaintiff. Old Dominion Branch 496, Nat'l Ass'n of Letter Carriers v. Austin, 418 U.S. 264, 281, 41 L. Ed. 2d 745, 94 S. Ct. 2770 (1974); St. Amant v. Thompson, 390 U.S. at 731; Reader's Digest Ass'n v. Superior Court, 37 Cal. 3d 244, 257, 690 P.2d 610, 208 Cal. Rptr. 137 (1984), cert. denied sub nom. Synanon Church v. Reader's Digest Ass'n, 106 S. Ct. 3307 (1986); Herron v. Tribune Pub'g Co., 108 Wn.2d at 170-71. However, actual malice can be inferred from circumstantial evidence, including defendant's hostility or spite, the reporter's knowledge that his sources are hostile to the plaintiff or ignorant of the details concerning the situation in question, destroying notes after the complaint is served, failure to follow newspaper procedures for filing papers of inaccuracy, and failing to properly investigate. See, e.g., Tavoulareas v. Piro, 759 F.2d 90, 134-35 (D.C. Cir. 1985); Reader's Digest, 37 Cal. 3d at 257-58.
Professions of good faith [by the defendant] will be unlikely to prove persuasive, for example, where a story is fabricated by the defendant, is the product of his imagination, or is based wholly on an unverified anonymous telephone call. Nor will they be likely to prevail when the publisher's allegations are so inherently improbable that only a reckless man would have put them in circulation. Likewise, recklessness may be found where there are obvious reasons to doubt the veracity of the informant or the accuracy of his reports.
St. Amant, at 732.
Individual factors that evidence actual malice are not generally sufficient to establish actual malice. For example, hostility alone will not constitute actual malice. McDonald v. Murray, 83 Wn.2d 17, 19, 515 P.2d 151 (1973); Reader’s Digest, 37 Cal. 3d at 258. A reporter's knowledge that his principal sources were hostile to the plaintiff will not of itself establish actual malice. Rye v. Seattle Times Co., 37 Wn. App. 45, 53-55, 678 P.2d 1282, review denied, 102 Wn.2d 1004, cert. denied, 469 U.S. 1087 (1984); Tilton v. Cowles Pub'g Co., supra at 722-23. Nor will mere failure to investigate in itself be considered bad faith. New York *525Times, 376 U.S. at 287; St. Amant, 390 U.S. at 733. Mistakes made in investigating a news story do not rise to the level of actual malice. Time, Inc. v. Pape, 401 U.S. 279, 292, 28 L. Ed. 2d 45, 91 S. Ct. 633 (1971); Marcone v. Penthouse Int'l Magazine for Men, 754 F.2d 1072, 1090-91 (3d Cir. 1985). However, each of the above factors may be taken into account cumulatively as probative evidence of actual malice. St. Amant, at 732; Herron v. Tribune Pub'g Co., 108 Wn.2d at 172.
Here, viewing the evidence in the record in a light most favorable to Herron, there is abundant circumstantial evidence of actual malice. McGaffin's exchange with Deputy Prosecuting Attorney Sebring was extremely hostile. McGaffin threatened to "get" Herron or his staff in a story he intended to broadcast on the evening news because he was angry at their failure to cooperate with his investigation. He then in fact did broadcast a story casting the prosecutor's office and specifically Herron in a very evil and criminal light in a story that contained inexplicable falsehoods. In addition, the general tenor of the story is hostile and even implies that Herron arranged court records to hide his illegal activities. See Goldwater v. Ginzburg, 414 F.2d 324, 337 (2d Cir. 1969) (innuendo can be indicative of actual malice).
The evidence viewed in a light most favorable to Herron indicates that McGaffin fabricated important portions of the story he broadcast on KING TV. Neither Hendry nor McBroom believes he told McGaffin that approximately half of Herron's campaign contributions came from bail bondsmen. McGaffin's assertion that he looked at the Public Disclosure Commission records of contributions before his broadcast, combined with the fact that the figures he reported were wildly different from the actual figures in the Commission's records raises an issue of fact as to whether he fabricated the figures. Although the contributions list includes over 500 names, there were only a few recognizable bail bondsmen's names, and the amounts contributed appeared next to each name. McGaffin could not explain *526why his news announcement stated that "approximately half" of Herron's campaign funds came from bail bond interests.
Moreover, although the statement in the 11 p.m. broadcast that Herron accepted $50,000 in bail bondsmen contributions is time-barred as a separate cause of action, it is evidence of a pattern of fabrication that the jury is entitled to consider in determining actual malice. Goldwater, at 337 (jury may consider totality of conduct to find actual malice).
There is evidence that McGaffin may have relied on sources he knew or should have known to be unreliable. McGaffin claims that either Hendry or McBroom told him that "approximately half" of Herron's campaign contributions were from bail bondsmen. However, because the 1974 election between Herron and Hendry was a bitter one, it is possible that (if Hendry or McBroom in fact gave him that information) McGaffin believed that both Hendry and McBroom were hostile to Herron. It is unclear from the record whether McGaffin had reason to doubt their information. Whether McGaffin knew that his sources were hostile to the plaintiff or ignorant of critical details was probative evidence of actual malice. Tavoulareas v. Piro, at 132.
Finally, it is unclear from the record whether the tape of both the 5:30 p.m. and 11 p.m. newscasts was destroyed out of sequence after the complaint was served.
In sum, a reasonable jury could look at several circumstantial yet probative factors to find that respondents published the statements with knowledge of their falsity or with reckless disregard as to their truth or falsity: the alleged threats that McGaffin would "get" the prosecutor's office; his review of public disclosure records; Hendry's and McBroom's denial of the "approximately half" of the money from bail bondsmen statement; his knowledge of the bitter 1974 election; and the possible improper destruction of the tape memorializing the news broadcasts. Herron has *527presented sufficient evidence to make a prima facie showing of actual malice.
Conclusion
Although CR 15(c) does not permit amendment to add a cause of action for the 11 p.m. newscast of December 1, 1978, the gist or "sting" of the 5:30 broadcast was itself materially false. While no single factor establishes actual malice, several factors are probative evidence of actual malice. A reasonable jury could find that these factors taken together show actual malice with convincing clarity. Herron was entitled to a trial on the merits on his defamation action.
Summary judgment of the Superior Court is reversed and the case is remanded for trial.
Utter, Brachtenbach, Dolliver, Callow, and Goodloe, JJ., concur.