Several witnesses took the stand Monday during the first day of witness testimony in the Julie Schenecker murder trial.

In addition to testimony from two of the first Tampa police officers on the scene, a neighbor who drove the carpool also testified.

And former Hillsborough County Medical Examiner Dr. Bernard Adams gave graphic testimony regarding the murders.

Julie Schenecker, 53, is accused of shooting her children, Calyx, 16 and Beau, 13. The children were found dead in their Tampa Palms home in January 2011.

Schenecker, who has a history of depression and a bipolar disorder, has pleaded not guilty by reason of insanity. If found guilty, she could be sentenced to life in prison.

Tampa Police Officer Gregory Noble was the first witness called to the stand Monday morning. Noble was the officer who responded to the Schenecker New Tampa home on Jan. 28, 2011.

Prior to Noble's testimony, attorneys used their opening arguments Monday to present very different views of the New Tampa mother.

In opening arguments, State Assistant Attorney Stephen Udagawa presented a picture of premeditated killings.

Udagawa said Julie Schenecker went to the Lock and Load gun store in Oldsmar days before the killing. He also pointed to entries in Julie Schenecker’s journal that presents a clear mind and a planned massacre.

The prosecution also described the murders in detail.                                       

“She’s driving, Beau is to her right,” Udagawa said, describing when Beau Schenecker was killed. “Points [the gun] at his head, bam! She shoots him in the left side of the head. Shoots him dead at close range.”

Then, he detailed Calyx’s death.

“[Julie] goes upstairs where Calyx is working on her computer,” Udagawa said. “She walks up close behind her and Calyx says, ‘What are you doing?’ The defendant responds, ‘Just seeing what you’re doing.'

“Raises the gun up, bam! Shoots her in the back of the head.”

The state went on to say that she shot both of the children in the head and in the mouth - in the mouth because they had been talking back to her.

The defense, however, used its opening statements to describe an increasingly severely ill woman who was not in charge of her actions.

Defense attorney Jennifer Spradley said Julie Schenecker was molested as a child and again as a teenager. She described Schenecker’s bipolar condition and her numerous treatments for her disorders over the years.

Spradley also said that Julie Schenecker had planned to kill herself as well.

“We are going to ask you to find her not guilty by reason of insanity,” Spradley said.

The testimony started after a weeklong jury selection process. Attorneys had some difficulty finding jurors who had not heard about the case.

Before court began, Col. Parker Schenecker, Julie's Schencker's former husband made a brief statement to media members. He said the focus now is on "getting Calyx's and Beau's voices" and that he would continue to do work in their names.

The trial is expected to last about two weeks.

Bright House Networks cable subscribers can watch the trial live on Channel 314 in the Tampa Bay area.

Text of Col. Schenecker's statement

Here is the text of the statement made by Col. Parker Schenecker before court opened Monday:

"Good morning. As I've told a lot of you along the way, it's been a long long road to get to today. I want to thank you very much for your continued support and love of Calyx and Beau and my family, and your continued coverage of our great work. We've been working from nonprofits and trying to get something back to the community.

"Today, for the next couple weeks, the focus is really on getting Calyx's and Beau's voices. So thank you very much."

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