A Canadian, Cooper didn't have a visa to work in the United States. This spring, months before her slaying, Cooper wanted to go home to Canada, but her husband hid the passports of their U.S.-born daughters, Nancy Cooper's family alleges in a custody complaint filed in Wake County on Wednesday.

Legal wrangling over the care of Isabella, 4, and Gabrielle (called "Katie"), almost 2, offered a window into Nancy and Bradley Cooper's troubled marriage. Nancy's father and sister were granted emergency custody of the girls Wednesday night. They said in court documents that Bradley Cooper posed a threat "to the physical safety of the children."

Bradley Cooper's attorneys declined to comment Thursday. He'll have a chance to challenge his lost access to his daughters at a hearing July 25 at which his wife's family will ask a judge to make their custody more permanent.

Nancy Cooper, 34, vanished Saturday. A walker found her body Monday, dumped near a storm drain in an unfinished subdivision near her home. Cary police worked Thursday to scour the couple's home, looking for clues to help find her killer.

For days, Cary police have hovered about Bradley Cooper. The two-story Lochmere subdivision home he shared with his wife was declared a crime scene. He'd been caring for his daughters 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 Khrista Lister.

A judge grants emergency custody to those other than a child's parent only when he thinks the child's welfare is in jeopardy.

According to the custody complaint, Cooper's family said she had been desperate to leave her marriage and join her twin sister in Canada. Bradley Cooper had been unfaithful, the family said, and had been yelling at and belittling his wife in front of their children. Bradley Cooper also had been withholding money, her family said, adding that they had been lending her cash to buy groceries for her and the children.

At first, Bradley Cooper told his wife that she and the children could go to Canada, according to the petition. But this spring, her family said, Bradley Cooper took the girls' passports from Nancy Cooper's car, essentially holding them captive in North Carolina.

The Coopers' children were born in the United States and needed passports to travel to their parents' native country. Children traveling to Canada with only one of their parents also must have written permission from the other parent to enter the country, according to Canadian immigration rules.

Nancy Cooper's legal status in the United States would have been tied to her husband, immigration lawyers said Thursday. The couple had not yet received green cards or permanent resident status; Cisco Systems, Bradley Cooper's employer, had applied for a set for the couple, friend Brett Adam said.

If Nancy Cooper had left her husband, she might have jeopardized her standing in the U.S.

"Whatever status she had is dependent on his status and his willingness to include her," said Jack Pinnix, a Raleigh lawyer who specializes in immigration law but is not involved with the Coopers.

Nancy Cooper came to the United States on the coattails of her husband. He'd worked for Cisco in Calgary and accepted a transfer to their division at Research Triangle Park. The company secured Bradley Cooper a temporary work visa; Nancy Cooper's was attached to his.

To move to the U.S., Nancy Cooper shelved a budding career in the tech world and left a clothing boutique she ran in Calgary, her friends have said. Here, friends said, Nancy Cooper's visa didn't allow her to work, so she raised her daughters full-time.

"We had talked about how difficult it could be to be confined," said Adam, a friend of Nancy. "But it was a reality that she chose and knew -- for Nancy being a mother was everything."

Isabella and Katie Cooper will now go to Canada. A judge ordered Bradley Cooper to turn over their passports.