SELECT DISTINCT Parent.successionID
INTO :successionID
FROM EvidenceDescriptor Parent
INNER JOIN EvidenceRelationship ON Parent.evidenceType = EvidenceRelationship.parentType
AND Parent.relatedID = EvidenceRelationship.parentID
INNER JOIN EvidenceDescriptor Child ON Child.evidenceType = EvidenceRelationship.childType
AND Child.relatedID = EvidenceRelationship.childID
WHERE Child.successionID = :relatedSuccessionID