Daniel Wallace/Tampa Bay Times/AP
05/15/2014 at 06:00 PM EDT
A jury found Julie Schenecker guilty of two counts of first-degree murder in the 2011 shooting deaths
of her children, 16-year-old Calyx and 13-year-old Beau.
The panel deliberated less than two hours Thursday before determining that the Florida woman was sane at the time she killed the teens. Judge Lamar Battles sentenced her to two concurrent sentences of life in prison without the possibility of parole.
"I apologize to everyone in this courtroom," Schenecker told the court, her voice racked by sobs. "I know I shot my son and daughter. I don't know why. I have a period of time to try to understand that.
"I know that my children are in heaven," she continued. "I want people to try to find comfort in believing, as I do, that they are in no pain and they are alive and enjoying everything and anything that heaven has to offer. Jesus is protecting them and keeping them safe until we get there."
As Schenecker spoke, her mother sobbed in the front row.
After the verdict, Schenecker's ex-husband, Parker, addressed the media.
"Today's verdict give our family a sense of relief," he said. "The most important thing in all of this are Calyx and Beau, my lovely children. My smart, beautiful, loved and missed daughter and son. Giving them a voice has been my priority throughout this process. This decision gives our family an opportunity to move forward."
It was a dramatic end to nearly two weeks of disturbing and often macabre testimony.
Jurors had seen autopsy photos of the teens, who were each shot twice: once in the head, and once in the mouth.
During Wednesday's testimony, they heard that Schenecker had manipulated her slain daughter's mouth
into a smile after the shooting.
Schenecker's attorneys argued that she was insane at the time of the shooting, but prosecutors maintained that they were calculated murders by a woman who knew the difference between right and wrong.