TAMPA — A jury took less than two hours Thursday evening to find Julie Schenecker guilty of murdering her two teenage children three years ago by shooting them at close range in the head and mouth.The jury of eight men and four women, most of them parents themselves, found her guilty of first-degree murder and rejected her attorneys' insanity defense. With her eyes red from crying throughout the trial, Schenecker received the mandatory life sentence impassively, before the bailiffs shackled her arms and legs.Schenecker, 53, who has spent most of her adult life struggling with bipolar disorder, then rose to her feet and delivered a long and at times bizarre statement to the court."I apologize. I apologize to everybody in this courtroom . . . the lives I have destroyed," she said in a thin, child-like voice, at times crying and pausing to regain her composure. "I take responsibility. I was there. I know . . . I know I shot my son and daughter. I don't know why.''She praised the U.S. justice system, Hillsborough Circuit Judge Emmett L. Battles and the attorneys provided to her by the public defender's office after her assets were frozen as a result of the divorce that followed her arrest.Remnants of her nearly decade-long career in the military stayed with her as her speech took an unusual turn and she told the court: "I'm proud to stand here in front of you," like a battle-tested soldier about to receive the Purple Heart.She said she was sorry to her family and to anyone who had known her 16-year-old daughter, Calyx, and 13-year-old son, Beau."I understand that there are people who are affected by this who may have just read about it in the paper," she continued. "Or maybe a child looked at their mommy and said, 'Mommy, are you ever going to shoot me?' I know this could happen and I apologize for what happened, what I did.''Schenecker sat down and buried her face in tissues. Seated several rows behind her, her sister began to sob."It's almost too much for us to comprehend what brings us here," said Judge Battles. "Regrettably, there's nothing this court can say or do to bring comfort to all those touched by this tragedy."After the trial concluded and her sentence was read, Schenecker's ex-husband, former Army Col. Parker Schenecker, delivered a brief statement to a crush of reporters, taking no questions. Through a full week of jury selection and two weeks of trial, he has sat, virtually expressionless, but keenly interested in the outcome of a legal drama that, for him, is unlikely to conclude with this trial. He filed a wrongful death lawsuit against his ex-wife after her arrest. It remains open."Today's decision, for many reasons, gives my family a great sense of relief," he said. "As I have consistently mentioned for the past three years, the most important thing in all of this is Calyx and Beau, my lovely children, my smart, beautiful, loved and missed children."Though prosecutors had initially planned to pursue the death penalty in this case, they reversed course last month, declaring that Schenecker's mental health issues were so severe that the state Supreme Court would not uphold a death sentence against her. Jurors were instructed that they could consider the lesser charges of second-degree murder and manslaughter, possibilities they rejected.The unusually short deliberations followed two weeks of expert testimony, recitations of Schenecker's history of psychiatric problems, and readings aloud from her journal, the spiral-bound notebook where she detailed her thoughts before and after the killings.Her confession to Tampa police detectives was played for the jury, who listened to her admit that she'd shot her children and then ask the detectives: "Are my kids coming in later?"Attorneys for Schenecker had argued that she was legally insane and unable, due to her bipolar disorder, to distinguish between right and wrong. They pointed to entries in her journal, particularly the last one she'd written before she fell asleep, having overdosed on Lithium and the blood thinner Coumadin after killing her children. "We're going home today, take us home Lord," she'd penned. Later, after her arrest, Schenecker would say that she had bought a .38-caliber revolver to kill herself — something she'd long contemplated. But the thought occurred to her that she could take her children with her, saving them from the pain they might experience if they inherited her bipolar disorder. Killing her children didn't seem wrong to her, said her attorney Jennifer Spradley.Prosecutor Jay Pruner also used entries in Schenecker's journal to prove to jurors that the suburban stay-at-home mom who lived a comfortable life in New Tampa knew exactly what she was doing."I will pick up the gun on Thursday," she'd written, adding that she would then put her son, Beau, to bed. She debated whether she'd turn on the lights to blind him and how many bullets it would take to kill him. She didn't want to have to reload. "I'm nervous," she wrote. Schenecker was mentally ill, Pruner acknowledged, but in January 2011, when she shot both of her children, she was not so sick that she wasn't in full control of her actions. She had killed out of anger at her husband, he said. "Because she felt abandoned, betrayed, and despondent."Juror Cheri Kendall, 42, told the Tampa Bay Times that during deliberations, the jury read Schenecker's journal cover to cover. In it, they found proof of premeditation and evidence she'd known that society would view her actions as morally wrong and illegal. That Schenecker had lied to the gun store clerk, telling him that she needed the weapon for self-defense, weighed heavily in her thinking, Kendall said. "We had some discussions on how do you really know what is going on through someone's mind, but we kept coming back to what the law states constitutes insanity," she said. "Being mentally ill is not the same as being insane."In her address to the court, Schenecker said that she was certain her children were in heaven."I want people to try and 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," she said. "Jesus protect me now. Keep them safe until we get there and their loved ones follow us to join them."Times staff writers Keeley Sheehan, Jamal Thalji and Patty Ryan and news researcher John Martin contributed to this report. Anna M. Phillips can be reached at [email protected] or (813) 226-3354.