Vigilante and Psychologist. What a deadly combination.
Almost a full-blood Italian, she has smooth, olive-toned skin; rarely touched by the sun for too long--she's slightly paranoid about cancer. She stands at about 5'10", her overall body long and slender, like an Italian leopard. She has black hair that cascades down her shoulders like a waterfall, almost frozen in time. Her posture conveys confidence, almost to the point of arrogance. She walks with purpose, rarely ever not having something to do, or somewhere to go. Her green eyes stand out against her complexion and her hair, making them one of her best and brightest features. Although they may appear green, they're actually a hazel color that veers towards the green.
Often described as likable, charming, but somewhat curt, Isabella never stands out because of who she is; at least not to those who don't know her inner self. Because of her past, which is explained later, she developed Psychopathy, a mental disorder which inhibits the brain's ability to process and produce chemicals needed to "feel". She quite literally has no emotions.
Her view of the world, now greatly hindered by her lack of emotions, revolves solely around what is wrong with the judicial system. She feels that the law cannot fully give killers and criminals what they so often deserve: death. She works for the Atlanta Police Department and does Psychological profiling for the FBI and the department. She specializes in serial killers, arsonist, and rapists. So, she works with people who are actually hunting people exactly like her... How's that irony for you?
She wears normal, medium-class clothing. She kills with a taser.
She was raised by Sam and Jill Costa in Atlanta, Georgia with one sister, no brothers. Her father, a lawyer, worked in a firm he began building straight out of school using the money from his rich parents (who owned a winery in Italy). He is now retired and living happily in a tiny cottage in Vermont. Isabella's mother, Jill, was an accountant who worked for Sam in his firm, handling the money. She also retired with Sam and lives with him in the cottage.
The family of four lived happily in a two bedroom, two bath house in the suburbs of Atlanta. Isabella was showing real promise, as was her sister, but when a serial rapist/sadistic-torture-murderer decided to target Isabella's sister, Melody. Melody was kidnapped, raped, tortured, and murdered. Since then, Isabella has spiraled downward. Because the killer was never captured, only suspected, Isabella began to see the judicial system as faulty.
Her first kill was the man who killed her sister: Billy Rosena. She went on to kill more, and more, depending on where you pick up on her history.