In the first season, she hands Booth the file on her parents' disappearance and he agrees to look into it as a personal favor. It is later revealed in Season 2 that her parents, who were bank robbers specializing in safety deposit boxes, changed the family's identity after they stole some damaging FBI documents regarding the murder of an FBI agent and the false imprisonment of civil rights activist Marvin Beckett. Brennan's birth name was Joy Keenan. Her mother (real name Ruth Keenan, known under the assumed identity of Christine Brennan) had hoped to someday return to her children and family but made a tape for Brennan to watch on her 16th birthday in case that never happened. Brennan later discovered that Ruth/Christine was murdered in 1993, two years after she and her husband went on the run.