In about 70% of cases, the allegation is deemed to be unnecessary or false. Source: Johnston J et al. Allegations and substantiations of abuse in custody-disputing families. Family Court Review, Vol. 43, No. 2, 2005. & Foster BP. Analyzing the cost and effectiveness of governmental policies. Cost Management, Vol. 22, No. 3, 2008. 10, 11
I could not find the data via google scholar but instead found this part:
CUSTODY DISPUTES INVOLVING ALLEGATIONS OF DOMESTIC VIOLENCE: TOWARD A DIFFERENTIATED APPROACH TO PARENTING PLANS - Peter G. Jaffe, Janet R. Johnston, Claire V. Crooks, Nicholas Bala - 2008
Multiple, serious conflicting allegations of child maltreatment, domestic violence, and parental abuse of drugs and alcohol are commonly raised in high-conflict custody-litigating postseparation families. Substantiation of claims can be difficult, which poses great challenges for professionals involved in making parenting plans. With regard to substantiation of those claims, published research is limited, and studies are mostly of small and nonrandomly drawn samples, but findings from the few studies that exist indicate a significant proportion of domestic violence allegations (50–75%) and child abuse allegations (22–52%) in family law matters can be subsequently substantiated in some manner (Bala, Mitnick, Trocmé, & Houston, in press; Bala & Schuman, 1999; Brown, 2003; Johnston,
Lee, Olesen, & Walters, 2005; Shaffer & Bala, 2003; Thoennes & Tjaden, 1990).
It took me a while to understand that paragraph. This means that about 25-50% of DV allegations and 48-78% of child abuse allegations can NOT be substantiated. That is a whole lot if you ask me. But again, data is not rock solid.