I don't think she snapped.
My guess is she is a sociopath (anti-social personality disorder) just like Ted Bundy and Scott Peterson.
They are smooth.
They are often intelligent.
They are arrogant.
They are socially adept and, often, attractive and charming.
They are self serving.
They are fabulous liars.
They show no remorse.
They are master manipulators.
Get in their way, they won't hesitate to take you down.
Laci Peterson got in the way of Scott's new girlfriend.
I'm not sure what Travis did...maybe he got in the "way" by not committing to Jodi. Only she knows.
But her calm interview was no different than Scott's calm interview (at least he manufactured some fake tears).
Why take pictures afterwards?? Maybe she was proud of the "work" she did. Or she wanted to capture his last moments as a way to "own" him forever.
I'm guessing the whole thing was calculated...from bringing the gun, to having some fun and then, finally, taking photo's of the carnage.
It's easy to be calm in interviews and smile in mugshots when you have no remorse.
During the trial, she will likely be dolled up, smiling, waving to her family, like she doesn't have a care in the world.
They say sociopaths are people without conscious. Empty souls.
My guess??
Jodi is an empty soul.
