TAMPA, Fla. — In January 2011, just days before police said she shot her two teenagers to death for being “mouthy,” Tampa mom Julie Schenecker wrote in her journal about taking her son to soccer practice and making her daughter’s favorite chicken dinner.

She also detailed a fight she had with her daughter, how the 16-year-old called her “pathetic” and an “evil soul.”

“The evil starts Thursday,” Schenecker wrote, according to Matthew Evans, a Tampa Police crime scene technician, who read parts of the chilling journal passages Monday afternoon during Schenecker’s murder trial.

The 53-year-old former Army linguist has pleaded not guilty by reason of insanity to two counts of first-degree murder. Police say Schenecker fatally shot Calyx, 16, and Beau, 13, in January 2011 while then- husband Parker Schenecker was deployed overseas. The two have since divorced, and he is expected to be a witness for the defense.

Her defense attorney said she was a sick, troubled member of an all-American family, one who was sexually abused as a child.

But prosecutors told jurors that the woman planned a “Saturday massacre” and wrote coldly in her journal about how she “offed” her two teenage children.

On Jan. 22, Schenecker bought a .38-caliber handgun. She lamented the three-day wait for a background check in her journal, and when she collected the gun, she bought hollow point bullets, prosecutors said.

“I was planning on a Saturday massacre,” she wrote.

On the way to soccer practice in the family minivan, she shot Beau twice, investigators found – once in the side of the head and once in his mouth, prosecutors said.

She turned around, drove home and parked in the garage. Schenecker approached Calyx from behind and shot her once in the head and once in the mouth, Prosecutor Stephen Udagawa said.

Schenecker wrote about the shootings in her journals, saying that she shot both teens in “their mouthy mouths.”

She also put a sticky note on the calendar that said, “Beau is in the van on the way to practice. Calyx is in her bed, tried to make her comfortable.”

In her journal, Schenecker addressed her husband, writing that he was lucky he wasn’t in the house, prosecutors said. “I might have taken you out, too,” she wrote.

Schenecker had planned to kill herself, too, and told detectives after her arrest, “This is the worst thing I’ve ever done,” Udagawa said.

In her journal, Schenecker wrote that she wanted to kill herself and wanted herself and her children to be cremated, their ashes mixed together. She mentioned that she was going to try to move her son’s body into her bed and wanted to die next to him.

“Beau and I are going to heaven,” she wrote. “Wish heaven for Calyx too.”