The complex tort of malicious prosecution is frequently threatened yet rarely fully understood. One of the trickier elements to establish is that the prior action was filed and/or continued without probable cause. Just because you won the prior lawsuit does not necessarily mean that California courts will recognize the prior action lacked probable cause. "Reasonable Attorney" Test The test is whether any reasonable attorney would have thought the claim tenable. ( Sheldon Appel Co. v. Albert & Oliker (1989) 47 Cal.3d 863, 886). A claim is legally tenable if it is supported by existing authority or the reasonable extension of that authority. ( Sheldon Appel Co. v. Albert & Oliker, supra, 47 Cal.3d at p. 886; see also Arcaro v. Silva and Silva Enterprises Corp. (1999) 77 Cal.App.4th 152, 156-57). A claim is factually tenable if there is evidence sufficient to prevail in the action or at least information reasonably warranting an inference that there is such evidence. ( Arcaro v. Silva and Silva Enterprises Corp., supra, 77 Cal.App.4th at pp. 156-57; Puyear v. Golden Bear. Ins. Co. (1998) 66 Cal.App.4th 1188, 1197.) "A litigant will lack probable cause for his action either if he relies upon facts which he has no reasonable cause to believe to be true, or if he seeks recovery upon a legal theory which is untenable under the facts known to him." ( Cheong Yu Yee v. Cheung (Cal. Ct. App., Oct. 4, 2013, D060989). Determining "Probable Cause." The question of "probable cause" is an issue for the court not a jury, to decide unless facts known to attorney are disputed. ( Sheldon Appel Co. v. Albert & Oliker, supra, 47 Cal.3d at p. 875). "Probable cause" is evaluated under an objective standard. The attorney’s subjective intent is irrelevant to probable cause determination. ( Id. at p. 881). Expert testimony is inadmissible on the issue of the existence of probable cause. ( Id. at, 881). Probable cause must be independently established as to each separate claim. ( Crowley v. Katleman (1994) 8 Cal.4th 666, 679; Videotape Plus, Inc. v. Lyons(2001) 89 Cal.App.4th 156, 161. Establishing "Probable Cause" through Prior Rulings on the Merits In the prior action, certain rulings by the trial court may establish that the prior plaintiff had probable cause. For example, the denial of a defense motion for non suit followed by a plaintiff's jury verdict will establish probable cause even if the prior verdict is reversed on appeal. ( Cowles v. Carter (1981) 115 Cal.App.3d 350, 356). Likewise, the denial of a defense summary judgment will also establish that the prior action had probable cause. ( Roberts v. Sentry Life Insurance (1999) 76 Cal.App.4th 375, 384) An attorney should be consulted to advise you about your potential rights and defenses in a malicious prosecution action. Each case is different and you should consult a lawyer rather than relying on this post as legal advice for your situation.