Generally, parents have the ability to decide what is best for their children, which includes with whom the children interact. But the law allows for grandparents or other third parties to seek custody or court ordered visitation with minor children in some very specific circumstances. That said, there is an important distinction between a grandparent or other third party seeking custody of a minor child as opposed to visitation with a minor child.
In general, unlike visitation, third parties (including grandparents) cannot initiate a custody action in family court. Third parties can, however, seek to intervene in an already pending custody proceeding. In order to potentially gain custody of a minor child, the intervening third party must prove by a fair preponderance of the evidence factors demonstrating that he or she has a relationship with the child akin to that of a parent, that parental custody clearly would be detrimental to the child, and upon a finding of detriment, that third party custody would be in the child's best interest.
Third parties can seek visitation without a pending action so long as certain criteria are met. Generally, if a grandparent or third party can prove to the Court by clear and convincing evidence (which is the highest evidentiary standard of the Court) that (1) a parent-like relationship exists between the grandparent/third-party and the child and (2) denial of visitation would cause the child real and significant harm. In making its determination, the court may consider the effect that such visitation will have on the relationship between the child and his or her parents or guardians and the effect on the child of any domestic violence that has occurred between or among parents, grandparents, and the child, among other factors.