When the Dead Speak by Therese Szymanski

Having convinced the police and rival gang members that she is dead, former underworld figure Brett Higgins has moved to California and is living with her lover, Allie Sullivan, under the assumed name of 'Samantha Peterson.' The move out west gave her what she needed most - a chance to escape her brutal past and start over again.

Safe in Allie's arms, Sam almost believed that she could change her life as much as she had changed her name. But somewhere deep inside, Sam knew there had to be a price to pay for the trail of bodies they had left behind them. She had no idea how high that price would be. Until she found the gleaming butcher's knife... and the blood-soaked clothes...