El Dorado County Department of Human Services v. R.D., 159 Cal. Rptr. 3d 224

E.D. (born 2003) is the child of R.D. (father) and M.W. (mother); he was removed from mother's custody in 2009 due to substance abuse and placed with father.
Mother regained custody in 2010 in family court following a domestic violence incident; father had supervised visitation which was largely appropriate.
In August 2011, E.D. and his half-siblings R.R. and T.W. were removed from mother due to a drug relapse; the juvenile court assumed jurisdiction and placed the minors with the maternal grandmother, denying the Department’s recommendation for return to father.
In February 2012, the court expanded father's visitation and discussed overnight visits contingent on a Nevada ICPC home assessment; a formal overnight plan awaited further information.
The Department’s 12-month review (2012) recommended returning E.D. to father under a family maintenance plan supervised by Nevada; the minor favored living with father, but the maternal grandmother and others opposed the return; at the 12-month hearing the court found substantial risk of detriment if E.D. were moved and denied the return, prompting appeal and remand with directions to return the minor to father.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Whether return to father poses substantial risk of detriment.	Department supported return; no substantial risk shown.	Return would risk emotional harm due to current placement and relationships.	No substantial evidence supports detriment; reversal and return ordered.

In re Marilyn H., 5 Cal.4th 295 (Cal. 1993) (establishes high standard for substantial detriment in reunification cases)
David B. v. Superior Court, 123 Cal.App.4th 768 (Cal. App. 2004) (clarifies that substantial risk of detriment requires more than mere imperfection; must show risk to well-being)
In re Yvonne W., 165 Cal.App.4th 1394 (Cal. App. 2008) (requires consideration of parent’s efforts and progress in reunification)