July 9, 2013 Updated: July 9, 2013 at 7:00 pm
After weeks of quarreling with her mother-in-law, she offered her a home-cooked meal.
But when Ellyzabeth Joy Rainey put water on the stove to simmer, claiming she was making pasta, it was anything but a peace offering.
A Colorado Springs police detective on Tuesday described a two-hour interrogation in which he said Rainey, 20, freely recounted details of the April 3 slaying of Deborah Rainey. After first subduing the woman with scalding water in her apartment in the Tanager Meadows complex, 1384 Sandalwood Drive, Rainey allegedly said she bludgeoned her with free weights, stabbed her in the chest with a butcher knife and filled her mouth with bleach.
"She said she wanted to make sure she was dead," detective Shawn Peterson testified at a daylong pre-trial hearing for Rainey. A judge ruled that evidence against her is strong enough to try her on suspicion of first-degree murder.
Rainey, who will be held without bond at the El Paso County jail, is scheduled to return to court on Thursday for an arraignment.
At the time of the killing, Deborah Rainey, of San Francisco, had been visiting Colorado Springs to help take care of the couple's newborn child.
The Raineys' marriage - described by another investigator as "tumultuous" - further unraveled during the visit and they planned on getting a divorce, police said.
The probable cause ruling by 4th Judicial District Judge G. David Miller came despite arguments by her public defenders that Rainey is suffering from mental illness and didn't understand what she was doing.
Rainey, who was diagnosed with bipolar disorder at age 10, claimed she had been hospitalized in a psychiatric facility days before the killing after seeing hallucinations and becoming suicidal, though police say they have yet to corroborate that claim.
During her interrogation by Peterson, Rainey giggled nervously and spoke of "voices" that told her that her husband's mother was trying to "take everything away" from her, Johnson said in arguing that his client didn't have a "culpable mental state."
Prosecutors countered that Rainey appeared to understand the questions asked of her and displayed no obvious signs of mental distress.
Police said Rainey admitted to buying a set of knives two days earlier, which she said she hid in the laundry room. She also moved her husband's free weights from a bedroom into the living room in preparation for the attack, which allegedly commenced with Rainey dumping boiling water on the older woman as she checked Facebook on a laptop in the living room.
Deborah Rainey's son was at work during the attack on his mother, police said.
Whether the defense intends to offer an insanity plea should become clear at the arraignment scheduled for later this week.