A jury in Florida on Thursday found Julie Schenecker guilty of first-degree murder of her two teenage children, a boy and a girl.

Her defense had argued for an insanity plea, but the jury didn't buy it in the shooting deaths of her 16-year-old daughter Calyx and 13-year-old son Beau, reports the Tampa Bay Times. She murdered them both while her husband was on a 10-day deployment overseas.

She stood up and said, "I apologize. I apologize to everyone in the courtroom ... the lives I have destroyed. I hope they can collect themselves as best as possible, all of us and not just this courtroom."

Schenecker added, "I know I shot my son and daughter. I don't know why. But I have time to try to understand that.

She was sentenced to two life terms without the possibility of parole for murdering her children, according to The Associated Press. She shot Beau on the way to soccer practice and then drove home and shot her daughter from behind. Both children were shot in the head and "their mouthy mouths," her journal read.

Six mental health experts testified during the trial that Schenecker was mentally ill, but the prosecution counteracted that by having three experts testify that she was sane during the shootings.