Now You See Her by James Patterson

To save her own life, Nina Bloom vanished. Now, to rescue an innocent man, she confronts the killer she thought she had escaped forever.

A successful lawyer and loving mother, Nina Bloom would do anything to protect the life she's built in New York - including lying to everyone, even her daughter, about her past.

Nina's secret life began eighteen years ago. She had a carefree existence in Key West, a handsome police-officer husband, and a baby on the way. But Nina's world is shattered when she unearths a terrible secret that causes her to run for her life and change her identity.

Now, years later, when an innocent man is framed for murder, Nina knows she must return to Florida and confront the murderous evil she fled.