Canadian Nancy Cooper was trapped in America, her family indicated in court filings.
Cooper, whose body was found Monday by a storm drain near her home in the Raleigh suburb of Cary, didn't have a visa to work in the United States, friends and family said.
This spring, months before she was killed, Cooper, 34, wanted to go home, but her husband hid the passports of their American-born daughters, according to custody complaint filed by her family Wednesday.
Bradley Cooper had been caring for his daughters, Isabella, 4, and Gabrielle, almost 2, at the home of a friend until Wednesday night, when police turned them over to Nancy Cooper's father, Garry Rentz, and her twin sister, Krista Lister.
A judge only grants emergency custody to those other than a child's parent when he believes the child's welfare is in jeopardy.
Bradley Cooper's attorneys declined to comment Thursday.