Thereafter, petitioners filed renewed petitions for guardianship that were uncontested by respondents and granted by the probate court. Thus, the issue before us is technically moot. We address it, nonetheless, since the issue is one which is likely to recur, yet also is likely to evade judicial review. A trial court's determination regarding the existence of subject matter jurisdiction is a question of law that this Court reviews de novo. Probate courts are courts of limited jurisdiction and derive their jurisdiction and power from statutory authority.
Probate courts have exclusive jurisdiction over guardianship proceedings.
The court may order the department of social services or an employee or agent of the court to conduct an investigation of the proposed guardianship and file a written report of the investigation. The parental rights of both parents or of the surviving parent have been terminated or suspended by prior court order, by judgment of divorce or separate maintenance, by death, by judicial determination of mental incompetency, by disappearance, or by confinement in a place of detention. At the time the petitions were filed, the minor children's mother was deceased and their father was incarcerated. Moreover, Martin had permitted the children to reside with petitioners following their mother's death and before executing the power of attorney to Andrews without providing legal authority for the care and maintenance of the children upon his incarceration. It is clear from the plain and unambiguous language in the statute that the Legislature expressly intended for the probate court to assume jurisdiction over guardianship petitions under such circumstances, and we are not persuaded that Martin's execution of a power of attorney was sufficient to divest the probate court of jurisdiction over otherwise valid guardianship petitions.