The child, a boy, was 1 3/4 at the date of the alleged wrongful retention. He had lived in the United States all of his life. The parents were married and had joint rights of custody.
On 30 May 1991 the mother went to Switzerland, her State of origin, with the child to visit the maternal grandparents. They were scheduled to return on 3 July. They did not return. On 18 June 1991 the mother filed for divorce in the magistrate’s court of Thalwil, Switzerland. On 4 July the American Central Authority, on behalf of the father, applied to the Federal Ministry of Justice, the Swiss Central Authority, for the return of the child.
On 5 July the mother instituted divorce proceedings at the Horgen District Court. On 7 August the Federal Ministry of Justice instructed the Horgen District Court to suspend the divorce proceedings in accordance with Article 16 until a court decision on the return of the child had been issued.
On 5 September a petition was filed in the Horgen District Court for the return of the child. On 16 October the mother proved to the court that the return of the child could result in a serious danger of physical or psychological harm to the child. On 8 November an order was issued to commission an expert opinion on the matter.