What is the legal test for removing children from their parents under the Fourth Amendment?

In addition to the Fourteenth and First Amendment rights to familial association, "[w]e evaluate the claims of children who are taken into state custody under the Fourth Amendment right to be free from unreasonable seizures rather than the Fourteenth Amendment right to familial association." Kirkpatrick v. County of Washoe , 792 F.3d 1184, 1189 (9th Cir. 2015), on reh'g en banc , 843 F.3d 784 (9th Cir. 2016) (internal quotation marks omitted); see also Wallis v. Spencer , 202 F.3d 1126, 1137 n.8 (9th Cir. 2000) (holding that the childrens' claims "should properly be assessed under the Fourth Amendment"). Despite the different constitutional source of the right, we have held that "the same legal standard applies in evaluating Fourth and Fourteenth Amendment claims for the removal of children." Wallis , 202 F.3d at 1137 n.8.

We have woven these constitutional threads into a discrete constitutional right in cases where state officials remove children from parents without consent or due process. Our cases hold that the Fourteenth, First, and Fourth Amendments provide a guarantee "that parents will not be separated from their children without due process of law except in emergencies." Mabe v. San Bernardino Cty., Dep't of Pub. Soc. Servs. , 237 F.3d 1101, 110709 (9th Cir. 2001). Officials may not remove children from their parents without a court order unless they have "information at the time of the seizure that establishes reasonable cause to believe that the child is in imminent danger of serious bodily injury." Rogers v. County of San Joaquin , 487 F.3d 1288, 1294 (9th Cir. 2007) (internal quotation marks omitted). Such "reasonable cause" arises, for example, where

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