Cassidy Stay's testimony began with anecdotal stories about her family, her mother and father, and four siblings aged 4 to 13.
When asked about the attack in 2014, she recalled someone in a FedEx uniform knocking on the door. He was holding a duct-taped white pillow that prosecutors say Haskell brought to use as a silencer for a 9-mm handgun.
When she said her parents weren't home, he left but came back a few minutes later and entered the house. That's when the horror began.
Cassidy prayed as Haskell held her and her siblings at gunpoint, waiting for their parents to return from an errand. She testified Haskell was calm as he ordered them inside, threatening them with his gun.
Cassidy said, "I was trying to appeal to his humanity. I didn't think someone would hurt kids if he knew their names and how old they were."
Cassidy's mother Katie, father Stephen, and four siblings were all shot to death in their Spring home.
"The room smelled like blood. It tasted sour. It felt heavy and hot. There was no spirit in that room," said Cassidy.
Prosecutors say the family fell victim to a vindictive and vengeful Ron Haskell, the ex-husband of Katie Stay's sister Melanie. Haskell appears stoic in the courtroom, and his attorney told us he is sedated.
Ronald Lee Haskell Jr. faces multiple capital murder charges. He's accused of killing the family members as retribution for helping Melanie separate from him.
Another of Katie Stay's sisters also testified. Ariel Lyon talked about her concerns about Haskell's treatment of his children and how she feared him even before the events of July 9, 2014.
During the first day of the trial, the jury saw the gruesome pictures of the Stay family after they had been shot to death.
Tuesday morning, prosecutors showed more pictures, but this time, they showed a closer look of the bullets and a make-shift silencer allegedly used to muffle the sound of gunfire.
The jury also saw several pictures of shell casings, many of which were found alongside the victims, including Cassidy's brother, Zachary, her dad Stephen, and another was found near Katie.
Prosecutors also showed a picture of a bullet that ended up in Stephen's wallet. Stephen had the wallet on him during the shooting rampage.
The jury also learned there was no gun found at the home. During the morning session, Haskell showed little to no emotion and did not appear to look at the photographs.
The defense claims Haskell was insane at the time of the murders.
"He's sedated and he's an individual that's been treated for a severe mental illness," said defense attorney Douglas Durham on Monday. "Texas has an insanity statute and if this isn't a case where the evidence, a preponderance of the evidence, is going to show severe mental illness and he couldn't distinguish right from wrong, I don't know what case there is."
Haskell faces the death penalty if convicted.
TIMELINE: 6 members of Stay family killed in their home in Spring