Usually parents will have the best claim for custody of their child, however there are cases where somebody who is not a parent may be able to get custody of a child. The court will always consider what is in the “best interests” of the child, but our government has created laws which say that it is in the best interests of children to live with their parents wherever possible.
Another person may be able to get custody of a child where there is very bad behavior displayed by both parents or the parents have neglected the child to the point that Family and Children’s Services have taken the child away or are planning to take the child away. Even in situations where a child has been taken from their parents, Child and Family Services will almost always begin with a temporary residential placement of the child with the end goal being to return that child to their parents if the situation can improve.
Where a party has had custody of a child for some time and a parent has returned to attempt to claim that child, the situation may be different and will depend greatly on the specific circumstances of the case.