OPINION OF THE COURT
Levine, J. In December 1991, a child abuse petition was filed in the Family Court by petitioner alleging that Jamie TT., a female child then 13 years old, had been sexually molested by respondent, her adoptive father and the husband of her biological mother. Annexed to the petition was the affidavit of petitioner’s investigating caseworker. The affidavit related that Jamie had first disclosed to a school social worker and her guidance counselor in early December 1991 that respondent had fondled her breasts and vagina, that his sexual advances had begun over a year earlier when respondent had asked her to show her breasts to him, and that it had become progressively more intrusive and ultimately intolerable. Both educators spoke well of Jamie as an above-average student of good character and reputation.
*134Respondent denied the allegations of the petition and the matter proceeded to a fact-finding hearing, in which petitioner was represented by the County Attorney’s office and a Law Guardian appeared on Jamie’s behalf. The only witness called by petitioner was Jamie, who testified in detail concerning a history of sexual touching by respondent for more than a year, occurring most often on weekday afternoons after school during the one-hour period between respondent’s return from work and the mother’s return from work. Respondent testified on his own behalf, categorically denying engaging in any sexual abuse of Jamie. At the conclusion of the testimony, Family Court rendered a Bench decision stating that it was unable, subjectively, to resolve whether Jamie or respondent was telling the truth. The court therefore ruled that petitioner had failed in meeting the statutory burden of proving the allegations of the petition by a preponderance of the evidence, and the petition was dismissed. By consent of both parties, temporary custody of Jamie was continued with her grandparents. Petitioner and the Law Guardian appeal.1
The Law Guardian’s first point on appeal appears to be that, in failing to make a credibility determination as to the truth of either Jamie’s or respondent’s testimony, Family Court somehow abdicated its responsibility as the trier of fact and, therefore, this Court should assume that role or remit the matter for an entire redetermination. We disagree. Concededly, petitioner had the burden to prove the allegations of sexual abuse by a preponderance of the evidence (see, Family Ct Act § 1046 [b] [i]; see also, Matter of Tammie Z., 66 NY2d 1). This placed upon petitioner the risk of nonpersuasion of the trier of fact that the allegations of the abuse petition were more probably true than untrue (see, In re Winship, 397 US 358, 371-372 [Harlan, J., concurring]). Family Court’s frank acknowledgment of an inability to resolve the conflict between Jamie’s and respondent’s testimony left the court in equipoise as to which version of the facts was more probably true. This being so, the court was required to conclude that petitioner had failed to sustain its burden of proof. "If the plaintiff has not succeeded in fairly and reasonably convincing the trier of facts of the truth of his cause, or where he has left the trier of facts in such doubt as to be unable to decide the controversy, he has not sustained his cause by a fair preponderance of the evidence” (58 NY Jur 2d, Evidence and Witnesses, § 967, at *135720 [emphasis supplied]; see, Roberge v Bonner, 185 NY 265, 269; Richardson, Evidence § 97, at 74 [Prince 10th ed]).
Alternatively, the Law Guardian urges that there should be a reversal and a remittal for a new trial because Jamie was denied the effective assistance of counsel at the fact-finding hearing. The threshold issue on this contention is whether Jamie, as the subject of the child abuse petition brought under Family Court Act article 10, had a legally cognizable right to the effective assistance of counsel throughout the proceeding. We conclude that she did. First, New York statutory law guarantees a child, allegedly abused or neglected by a parent, independent legal representation in a Family Court Act article 10 proceeding (see, Family Ct Act § 249) based upon a legislative finding that "counsel [for minors in Family Court proceedings] is often indispensable to a practical realization of due process of law and may be helpful in making reasoned determinations of fact and proper orders of disposition” (Family Ct Act § 241).
We are also of the view, however, that the Due Process Clauses of the Federal and State Constitutions (see, US Const 14th Amend; NY Const, art I, § 6) mandate that there be some form of legal representation of Jamie’s interests in the proceedings on the petition. Jamie’s liberty interest was clearly at stake. The effect of Family Court’s exoneration of respondent was to restore to him the primary right to custody of Jamie.2 Upon the dismissal of the child abuse petition, decisional law made respondent’s right to custody of Jamie superior to third persons, including her grandparents, which could only be overcome by proof of extraordinary circumstances (see, Matter of Bennett v Jeffreys, 40 NY2d 543, 549; Matter of Sickler v Roach, 169 AD2d 874, 875; Matter of Bisignano v Walz, 164 AD2d 317, 318). Thus, custody and control of Jamie by the person she claimed had sexually molested her while in his prior custody were inextricably involved in the proceedings on the abuse petition. Moreover, once custody of her was restored to respondent, he had the right to invoke State sanctions against her in a person in need of supervision proceeding (see, Family Ct Act art 7) if Jamie challenged his authority by " 'ungovernable]’ ” behavior or running away (Besharov, Practice Commentary, McKinney’s Cons Laws of *136NY, Book 29A, Family Ct Act §712, at 21). We would be callously ignoring the realities of Jamie’s plight during the pendency of this abuse proceeding if we failed to accord her a liberty interest in the outcome of that proceeding, entitling her to the protection of procedural due process.
Applying the three-fold analysis of Mathews v Eldridge (424 US 319, 335), we have no hesitancy in concluding that the process due Jamie included effective legal representation of her interests during the child abuse proceedings against respondent. Notably, Jamie had a strong interest in obtaining State intervention to protect her from further abuse and to provide social and psychological services for the eventual rehabilitation of the family unit in an environment safe for her. Furthermore, Jamie’s interest in procedural protection was heightened because of the irreconcilably conflicting positions of her and her parents in this litigation (cf., Parham, v J. R., 442 US 584, 600-602). The governmental interest in this child abuse proceeding coincided with that of Jamie. As we said in Matter of Linda C. (86 AD2d 356, 361), "the interest in protecting children from the infliction of serious physical harm or sexual molestation by a parent is the apotheosis of the State’s parens patriae role”. The appearance of a lawyer to protect Jamie’s interests seems clearly necessary to avoid an erroneous outcome unfavorable to Jamie in the proceeding. A fact-finding hearing under Family Court Act article 10 on a sexual abuse charge is a completely adversarial trial with few deviations from the procedures applied in civil and criminal trials. A respondent parent in such a proceeding is afforded the full right to counsel, including assignment of an attorney if indigent (see, Family Ct Act § 262 [a] [i]). And, as previously noted, the risk of an erroneous factual determination rejecting Jamie’s claim of sexual abuse would be restoration of the custodial rights of the person accused of molesting her, a result we characterized in Matter of Linda C. (supra, at 360) as "approaching] the level of absolute abhorrence” and the Court of Appeals characterized as "disastrous” (Matter of Tammie Z., 66 NY2d 1, 5, supra).
Thus, Jamie had a constitutional as well as a statutory right to legal representation of her interests in the proceedings on the abuse petition. Her constitutional and statutory rights to be represented by counsel were not satisfied merely by the State’s supplying a lawyer’s physical presence in the courtroom; Jamie was entitled to "adequate” or "effective” legal assistance (Cuyler v Sullivan, 446 US 335, 344, 345; see, *137Matter of Karl W., 168 AD2d 997). No less than an accused in a criminal case, Jamie was entitled to “meaningful representation” (People v Baldi, 54 NY2d 137, 147). Effective representation for Jamie included assistance by an attorney who had taken the time to prepare presentation of the law and the facts, and employed basic advocacy skills in support of her interests in the case (see, People v Droz, 39 NY2d 457, 462).
Jamie did not receive the effective representation to which she was constitutionally entitled at the fact-finding hearing. In a child protective proceeding under Family Court Act article 10, such as the instant case, where the attorney for the petitioner child protective agency (here the County Attorney) presented the evidence in support of the petition in the first instance, it was the duty of Jamie’s court-appointed Law Guardian to insure that the evidence sustaining her allegations of sexual abuse by respondent was fully developed. "As the child’s advocate, the law guardian’s interest is to insure that, to the greatest extent possible, all relevant facts, expert opinions and records are introduced into evidence. Standards B-l and B-2 thus encourage the law guardian to be familiar with the possible evidentiary material, and to question and cross-examine witnesses whenever necessary for a full presentation” (Law Guardian Representation Standards [NY St Bar Assn Comm on Juvenile Justice and Child Welfare, 1988], Part III Child Protective Proceedings; Part B: The Fact-Finding Hearing, Commentary, at 145). Here, the presentation of the evidence by the County Attorney clearly required more than a passive role on the part of Jamie’s Law Guardian. In a case in which, foreseeably, the outcome inevitably would turn upon a determination of the credibility of Jamie or of respondent, the County Attorney failed to call the numerous witnesses to her out-of-court statements to confirm her testimony (see, Family Ct Act § 1046 [a] [vi]), expressly refused to explore the possibility of obtaining validation evidence from an expert witness, admissible to corroborate or bolster Jamie’s testimony (see, Matter of Nicole V., 71 NY2d 112, 121), and declined to conduct any cross-examination whatsoever of respondent. The Law Guardian did nothing to make up for these lapses in presentation of the evidence in support of Jamie’s allegations. The Law Guardian called no witnesses and engaged in only the most perfunctory cross-examination of respondent, consisting of only three questions, none of which had any bearing on respondent’s credibility.
The deficiencies noted cannot be explained as merely losing *138trial tactics. No conceivable forensic stratagem could justify the absence of preparation and advocacy skills shown here which in a criminal case would clearly have required reversal (see, People v Daley, 172 AD2d 619, 620-621; People v Echavarria, 167 AD2d 138, 139-141; People v Morales, 118 AD2d 814, 815; People v Worthy, 112 AD2d 454, 455-456). The Law Guardian’s failure to take an active role in the proceedings is alone sufficient to require reversal (see, Matter of Elizabeth R., 155 AD2d 666, 668).
Consequently, the order dismissing the petition should be reversed and the matter remitted to Family Court for further proceedings, including a new fact-finding hearing.
. Despite filing a notice of appeal, petitioner chose not to file a brief.
. Throughout the proceeding, Jamie’s mother supported respondent’s claim of innocence of the allegations of sexual abuse and she continued to reside with him.