Problem med dubletter

Har följande:

	SELECT c.ChildId, (c.LastName + ', ' + c.FirstName) AS Name, c.Picture, c.Birthday,  d.Name AS DepartmentName, isnull(s.Firstname+ ', ' + isnull(s.LastName, ''),'Saknas') AS StaffName, isnull(p1.Firstname+ ', ' + isnull(p1.LastName, ''),'Saknas') AS Parent1Name, isnull(p2.Firstname+ ', ' + isnull(p2.LastName, ''),'Saknas') AS Parent2Name
	FROM Child AS c

	INNER JOIN Department AS d
	ON c.DepartmentId = d.DepartmentId

	LEFT OUTER JOIN Staff AS s
	ON c.StaffId = s.StaffId

	LEFT OUTER JOIN ParentToChild AS ptc1
	ON c.ChildId = ptc1.ChildId

	LEFT OUTER JOIN Parent AS p1
	ON ptc1.ParentId = p1.ParentId

	LEFT OUTER JOIN ParentToChild AS ptc2
	ON c.ChildId = ptc2.ChildId AND ptc2.ParentId != p1.ParentId

	LEFT OUTER JOIN Parent AS p2
	ON ptc2.ParentId = p2.ParentId

	WHERE c.DepartmentId = @DepartmentId or @departmentId = 0

	ORDER BY c.LastName ASC, c.FirstName ASC

Denna fråga returnerar samma Child två gånger om den har två parent. Har provat med distinct, men blir ingen skillnad. Någon som har en lösning??

Tacksam för all hjälp :stud