OPINION
I. INTRODUCTION
Lee Lawson appeals the superior court's holding that his defamation claim against Ernie and Linda Helmer fails as a matter of law and the court's award of attorney's fees to the Helmers. We hold that the superior court correctly held that the Helmers' testimony and statements to a custody investigator are immunized from Lawson's derivative civil defamation suit. We affirm the superior court's dismissal of Lawson's claims and its award of attorney's fees to the Helmers.
II. FACTS AND PROCEEDINGS
A. Facts
Lee Lawson has known Ernie and Linda Helmer for over thirty years. Lawson and Ernie Helmer were best friends. Lawson and his former girlfriend, Tammy Reynolds, lived with the Helmers while Tammy was pregnant with his daughter Ariel. The Hel-mers were present when the child was born in January 1999, and consider themselves her "de facto grandparents." In May 1999 Lawson and Reynolds separated, thereafter engaging in a protracted child custody dispute.1
After Lawson's and Reynolds's separation, the relationship between Lawson and the Helmers deteriorated. Linda Helmer sought a long-term protective order against Lawson before Magistrate John W. Sivertsen, Jr. in November 1999. She testified that Lawson sexually assaulted her in 1991 or 1992 and had threatened her with violence on several occasions. Magistrate Sivertsen found by a preponderance of the evidence that Lawson committed a erime involving domestic violence against Linda Helmer and granted the protective order. The Helmers also became involved in the custody dispute before Superior Court Judge Patricia A. Collins. They testified in the custody dispute between Lawson and Reynolds and made statements to a court-appointed custody investigator who filed a report with the court. Over the *726course of the custody proceeding (1) the Hel-mers testified at trial that prior to Ariel's birth, Lawson planned to kidnap Kevin, his son from a relationship with a former girlfriend, Valerie Lawson; (2) Ernie Helmer stated to the custody investigator that Lawson admitted to Ernie that he obtained an "X-rated" video of Valerie during their eusto-dy dispute over Kevin, by breaking into her storage locker; (8) Linda Helmer stated her opinion that a gunshot wound sustained by Lawson during his custody dispute with Valerie was probably self-inflicted; (4) Ernie Helmer stated to the custody investigator that Lawson had a handgun of the type used to inflict the gunshot wound and had asked Ernie not to tell anyone about it; and (5) Linda Helmer testified that Lawson sexually assaulted her in 1992.
The superior court entered its findings of fact and conclusions of law and a custody decree continuing joint legal custody and granting primary physical custody of Ariel to Reynolds in December 20002.2 We upheld that decision.3
B. Proceedings
Lawson sued the Helmers for defamation based on their statements during the custody proceedings before Judge Collins and the protective order proceedings before Magistrate Sivertsen,. He claimed that the Hel-mers' statements on the above five subjects were false and defamatory. He sought nominal and punitive damages against the Hel-mers, as well as an order forbidding them from having any contact with Ariel.
On January 11, 2001 Judge Collins ruled that Lawson's claims fail as a matter of law. She also ordered him to pay the Helmers $6,174 in attorney's fees. Lawson appeals both the dismissal of his claims and the award of attorney's fees. The Helmers declined to file a brief.
III. STANDARD OF REVIEW
We exercise our independent judgment when reviewing issues of law, " 'adopt[ing] the rule of law that is most persuasive in light of precedent, reason, and policy' "4 The superior court's decision-that Lawson's claims fail as a matter of law due to the Helmers' witness immunity-concerns an issue of law that is subject to de novo review.
We also review constitutional questions de novo.5
IV. DISCUSSION
A. The Helmers' Testimony and Statements in Prior Judicial Proceedings Are Absolutely Privileged and the Helmers Are Accordingly Immune from this Action for Defamation.
Lawson asserts that the superior court's grant of immunity to the Helmers was improper, claiming that the court used immunity as a means to avoid admitting that it had made a mistake in the custody dispute after Lawson proved that the Helmers had committed perjury in that proceeding. Lawson misunderstands the superior court's application of absolute privilege and the resulting witness immunity for the Helmers testimony and statements to the custody investigator.6
*727As we said almost thirty years ago in Nizinski v. Currington: 7
The authorities are virtually unanimous that defamatory testimony by a witness in a judicial proceeding, which is pertinent to the matter under inquiry, is absolutely privileged. In such instances an action for libel or slander will not lie even though the testimony is given maliciously and with knowledge of its falsity.[8]
Because testimony that is pertinent to the matter under inquiry is absolutely privileged, the witness is immune from later suit.9 The Restatement (SEconp) or Torts § 588 provides that:
A witness is absolutely privileged to publish defamatory matter concerning another in communications preliminary to a proposed judicial proceeding or as a part of a judicial proceeding in which [the witness] is testifying, if it has some relation to the proceeding.[10]
Even defamatory testimony is privileged, and the witness granted immunity, because of the public policy rationale that the privilege leads to more just trials by (1) encouraging more witnesses to come forward and (2) ensuring that witnesses will be more open and honest in testifying.11 The widespread recognition of the privilege is predicated on the idea that parties are protected from witness misconduct by (1) their ability to reveal any deficiencies in testimony through cross-examination and (2) the threat of prosecution for perjury or other sanctions against the witness.12
While Nizinski v. Currington is dispositive of this case, our recognition of the privilege and resultant immunity from suit for defamation in Zamarello v. Yale13 is also instructive here. In Zamarello we held that a party to a property dispute is immune from suit for slander or disparagement of title when the party files a quitclaim deed that has a "direct relation to [the] claim of an interest in the property." 14 In recognizing the privilege for the filing of a quitelaim deed related to judicial proceedings, Zamarello effectively adopted the Restatement (Second) or Torts § 587,15 which provides:
A party to a private litigation or a private prosecutor or defendant in a eriminal prosecution is absolutely privileged to publish defamatory matter concerning another in communications preliminary to a proposed judicial proceeding, or in the institution of *728or during the course and as a part of, a judicial proceeding in which he participates, if the matter has some relation to the proceeding.
In sum, the Helmers testimony and related statements made during the course of the prior litigation were absolutely privileged and the superior court correctly determined that the Helmers were immune from Lawson's defamation action.
B. The Alaska and Federal Constitutions Do Not Require that the Hel-mers Be Found Liable for Defaming Lawson.
Lawson claims that the superior court's decision to grant the Helmers civil immunity when other people have been sentenced to serve time in jail and fined after being convicted of perjury violates the equal protection clauses of the state16 and federal17 constitutions. He further argues that the superior court's granting of immunity based on tort law should be reversed because it elevated tort law over the constitution. These constitutional claims are without merit.
Lawson does not state a cognizable equal protection claim, as "the basis of any equal protection claim is disparate treatment of similarly situated persons."18 Lawson fails to establish this fundamental aspect of an equal protection violation because his civil defamation case is so dissimilar to a criminal perjury case. The purpose of the perjury statute is primarily to protect the integrity of court proceedings,19 not to protect the object of the perjury, and we have never allowed a party to sue a witness for defamation. Furthermore, the fact that other citizens have been convicted of perjury in the past is irrelevant because the Helmers were not prosecuted for perjury. Lawson's equal protection claims must be denied because he fails to establish the most fundamental aspect of an equal protection claim: that he has been treated differently than a similarly situated person.
Lawson also contends that his right to relief in this case is supported by Alaska's constitutional qualification of the right to free speech. He argues that we must reverse the superior court's decision because the Alaska Constitution provides that everyone is responsible for the abuse of their right to free speech.20 In providing that citizens are responsible for abusing their right to free speech, the Alaska Constitution did not create an absolute right to sue others for defamation. Additionally, Alaska's perjury statute, AS 11.56.200, adequately fulfills any constitutional requirement that witnesses be held responsible for abusing their free speech rights.21
C. Lawson Has Waived His Claim That the Superior Court Erred by Awarding Attorney's Fees to the Helmers.
Lawson contends that the superi- or court erred by awarding $6,174 in attorney's fees to the Helmers under AS 09.30.065(a)(1). We have previously declined to reach an issue when a party mentioned it only in passing in his statement of the case, failed to discuss it in the argument portion of his brief, and devoted one sentence to argu*729ing the issue in his reply brief.22 In this case, Lawson fails to offer any support for his claim in the "statement of the issues for review" that the award of attorney's fees was unconstitutional because it places a deterrent on his right to "petition the government for a redress of grievances." Though we relax some procedural requirements for a pro se litigant where the litigant has made a good faith attempt to comply with judicial procedures,23 Lawson has not met this standard here. We decline to reach this issue because Lawson presented no argument at all in support of his claim.
v. CONCLUSION
Because immunity from derivative defamation suits is necessary to encourage the full and uninhibited testimony of witnesses such as the Helmers, and because Lawson was fully protected from any alleged misconduct of the Helmers by several procedural safeguards, we AFFIRM the superior court's decision dismissing the defamation suit as a matter of law. We also affirm the award of attorney's fees because Lawson waived the issue by failing to brief it adequately.