Her interrogator asked her how many times she thought it went off in her hands.
"A million times," she said. "It felt like a million times."
But Paolilla also had insisted that Snider forced her to take a gun.
"He's like come here, and then he shoved another gun and said 'just take this,'" she told police in a 2006 interrogation.
She added that Snider put his hand on top of hers, forcing her to fire.
"He was holding on to it, too," she told police. "... And I was scared and I was crying."
DeGuerin narrated his version of the scene for the jury.
"He put the .38 in her hands and she got it by the handle, and she's got her eyes closed," DeGuerin said. "He puts his hands over hers and he goes 1, 2, 3, bam, 1, 2, 3 bam."
Testimony about ballistics painted a different picture, however. Crime scene investigators pointed out that two victims, Tiffany and Adelbert, were found dead on the couch with their feet up, shot multiple times, with no sign of struggle.
Each was hit with bullets from two guns, the prosecution said, arguing that there were two shooters firing at the same time.
"It defies logic that this gun is emptied first and this gun is emptied second," said Craig Goodhart, a former prosecutor with the Houston District Attorney's office. "When you got multiple gunshots from both guns in the two kids on the couch who never move. ... These two guns were fired simultaneously."
There was also the question of why Paolilla didn't go to police after the murders. Paolilla had always said she didn't call the police because she was too afraid of Snider. But phone records show that she called him constantly after the crime.
"Over 1,100 calls are made from her to him and him to her," said Goodhart. "If you are so deathly afraid of someone, what are you doing on the phone with them? For over 1,000 phone calls!"
Finally the prosecution brought in their star witness: Paolilla's own husband, Justin Rott, who had joined her on an extended heroin binge in the months before her arrest. He said she had told him everything.
"She said before they walked into the house, Chris handed her a gun," Rott told the court.
A prosecutor asked, "Did she say, at this point, Chris forced it on her or ... threatened her?"
"No," said Rott.
The husband said Paolilla knew she was participating in a drug heist from the start, and when the bullets started flying, she didn't hesitate to join in.
"She said ... Chris shot first," Rott said. "[Then] she said they both started shooting."
In the most shocking moment of the trial, Rott described for the court what he said Paolilla told him about the final, cold-blooded minutes in the house.
"She told me that she told Chris that they had to go back," Rott testified. "She said she had to make sure they were all dead. ... She said when she went back in Rachael was there and she was still alive. She was choking on her own blood. She was gagging. She said that Rachael just kept asking, 'Why?'"
Then Rott described what happened next.
"She beat her to death. With the gun. She kept hitting her and hitting her and hitting her."
Family members of the victims were horrified and saddened listening to the testimony.