A Florida mother who admitted to killing her two teenagers in 2011 said she committed the murders because the kids were too "sassy."

In a recording played in court Wednesday, May 7, Julie Schenecker told a Tampa detective that she shot her 16-year old daughter and 13-year old son because they were "really mean" to her.

"I loved them when they were birth through six," Schenecker said on the taped conversation with Detective Gary Sandel. As the children got older, however, their relationship became turbulent.

"My daughter, the 16-year-old, is mouthy. She calls me names," she explained. Schenecker said that on January 27, 2011, everything came to a head.

"I just topped over. The last straw," she told Sandel.

Schenecker shot her son, Beau, twice in the head while she was driving him to soccer practice. She told police that the boy was "talking back" to her.

The military debriefer turned housewife then drove back home, leaving Beau's body in the minivan. She went into her daughter's room and shot Calyx in the head while the teen was on her computer.

The children's father, retired Army Colonel Parker Schenecker, was deployed at the time of the murders. He filed for divorce months after Julie's arrest.

Schenecker's attorneys say she suffers from bipolar disorder and depression. She told Det. Sandel that she was in therapy, and on several medications, including lithium.

Sandel said Schenecker was confused during the interview, and at times did not remember that she had killed her children.

"Are my kids coming in later?" she asked at one point.

She also had suicidal ideations.

"Beau went first, Calyx went second. I'd sure as hell like to go third," she said.

She also told police that she had planned to commit suicide after she killed the children, but could not explain why she did not go through with it.

Schenecker, 53, plead not guilty by reason of insanity to two counts of first-degree murder. Prosecutors have declined to seek the death penalty.