But the most revealing piece of evidence as to what happened in the house that day came from Christine's videotaped interrogation after she was arrested in 2006. She told police that Snider had a gun and forced her to take a second gun but that she never willfully fired it. Instead, she said, Snider put his hand on hers and caused her to fire the gun.
She said Snider later beat a severely wounded Rachael to death. According to Christine, Snider threatened to do the same thing to her and her family if she told anyone. She went to work at Walgreen's less than 30 minutes after the murders, instead of calling police.
A man Christine later married, Justin Rott, told police a different story. He said Christine admitted to going to the house to participate in a drug heist, and when Snider started shooting she didn't hesitate to join in. Rott said Christine told him that it was her, not Snider, who beat Rachael to death with a gun.
When the police finally caught up with Christine in July 2006, she was high on heroin, living in a hotel room strewn with used needles. She and Rott had been holed up in the room for over eight months.
In September 2008, she was convicted of murder and sentenced to life in prison. Christine is serving her time at women's penitentiary in Gatesville, Texas. Though she is not eligible for parole until 2046, she filed an appeal right after she was convicted.
"The statements she (Paolilla) made shouldn't have been submitted to the jury because she was under severe heroin withdrawal during the time of her interrogation by police," said Allen Isbell, Paolilla's lawyer.
Isbell also questions Christine's sentencing.
Though Christine was 17 years-old at the time of the murders, she was automatically sentenced to life in prison. Isbell argued before a Houston appeals court last December that "a mandatory life sentences in a murder case is unconstitutional for a defendant under 18 years of age."
The court has yet to rule on the appeal.
Meanwhile, the question still lingers: Why would Christine Paolilla kill her friends?
"I think there's a chance she thought they were pitying her ... but still envied them, because they didn't have to work so hard to be nice, to be accepted," Saltz said. "That's going to create some intense envy and jealousy, bring out the aggression, and the ... wish to punish them for what they have."
Houston Police Sgt. Brian Harris said in an interview with Deborah Roberts that he believes Christine still does not "own" the crime.
"For her to truly come to grips with what she had done," he said, "she has to acknowledge that there's a darkness in her soul."
Lori Paolilla now lives with the anguish of a mother whose daughter struggled with, and ultimately succumbed to, the harshness of the world around her.
"We represent parents who have teenage children... young adult children who are living in a world that was much different from when I grew up," Paolilla said. "Keep them away from the ones that you know in your heart are going to be the ones that can break them and weaken them and take them down."