In Re Joseph B.

The juvenile court found that Joseph B. (the minor) came within the provisions of Welfare and Institutions Code section 300, subdivisions (a) and (b), due to physical abuse by his mother, Alzata C. (Alzata), and father. (Further section references are to the Welfare and Institutions Code unless otherwise specified.) The minor was declared a dependent child of the court and was placed with his paternal grandmother.

Section 366.21, subdivisions (e) and (f), and section 366.22, subdivision (a), provide that, at periodic review hearings, the juvenile court "shall order the return of the minor to the physical custody of his or her parent or guardian unless, by a preponderance of the evidence, it finds that return of the child would create a substantial risk of detriment to the physical or emotional well-being of the minor."

At the 18-month review hearing, the court found that, although returning the minor to his parents would pose no risk of harm to the minor's physical well-being, it would cause a substantial risk of detriment to his emotional well-being because the minor's "mental health ... is at grave risk" if he is returned home. Nevertheless, the court…