Abigail Hernandez, the 15-year-old New Hampshire teen who was held against her will for nine months, knew the name of her kidnapper but did not reveal his identity to police until a week after she had returned home, ABC News reports.

Citing court documents released Wednesday, The Associated Press reports that Abigail told police that her captor unknowingly revealed his name to her when he handed her a cookbook with his name written inside. Her captor also reportedly handed her a ruler with the initials N.E.K. on it.

The court documents, according to The AP, reveal that at some point after Abigail’s return, her mother told police that her daughter “knew who her captor was.” The day before her captor’s arrest, Abigail provided police with his identity.

According to the Boston Herald, 34-year-old Nathaniel E. Kibby was arrested on July 28, 2014, approximately a week after Abigail return home. Kibby allegedly kidnapped the 15 year old as she walked home from school on October 9, 2013. The Boston Herald reports that Kibby is being held on $1 million bail.