A vexatious suit is the appellation given in Connecticut to the cause of action created by statute for the malicious prosecution of a civil suit, and which is governed by the same general principles as the common-law action of malicious prosecution.[1]  The elements of a common-law or statutory cause of action for vexatious litigation are identical.[2] 

            To establish a cause of action for vexatious suit, a plaintiff must prove, inter alia, that a prior suit was brought without probable cause.  See Conn. Gen. Stat. § 52-568.[3]  Lack of probable cause for institution of the original proceedings is the very gist of the action for vexatious litigation.[4]  The existence of probable cause is an absolute protection and what facts, and whether particular facts, constitute probable cause is always a question of law.[5]

            The test for deciding whether a litigant acted with probable cause is well settled.  For purposes of a vexatious suit action, the legal idea of probable cause is a bona fide belief in the existence of the facts essential under the law for the action and such as would warrant a man of ordinary caution, prudence and judgment, under the circumstances, in entertaining it.  Probable cause is the knowledge of facts, actual or apparent, strong enough to justify a reasonable man in the belief that he has lawful grounds for prosecuting the defendant in the manner complained of.  Thus, in the context of a vexatious suit action, the defendant lacks probable cause if he lacks a reasonable good faith belief in the facts alleged and the validity of the claim asserted.[6]

            The other essential elements of a common-law claim for vexatious litigation (in addition to lack of probable cause) are malice and a termination of suit in the plaintiff’s favor.  Malice may be inferred from lack of probable cause.[7]  The want of probable cause, however, cannot be inferred from the fact that malice was proven.[8]

            A statutory action for vexatious litigation under Conn. Gen. Stat. § 52-568 differs from a common-law action only in that a finding of malice is not an essential element, but will serve as a basis for higher damages. In either type of action, however, the existence of probable cause is an absolute protection against an action for malicious prosecution.[9]

            A vexatious suit is a type of malicious prosecution action, differing principally in that it is based upon a prior civil action, whereas a malicious prosecution suit ordinarily implies a prior criminal complaint.[10]

            Advice of counsel is a complete defense to an action of vexatious litigation when it is shown that the defendant instituted a civil action relying in good faith on such advice, given after a full and fair statement of all facts within his knowledge, or which he was charged with knowing.[11]  The fact that the attorney’s advice was unsound or erroneous will not affect the result.[12]