Cumberland Teen Pleads Guilty To Stepfather's Murder

In summer 2002, Army Maj. David Shannon was shot to death while he slept. Shannon's wife, Joan, blamed intruders, but a few days later, officers arrested Elizabeth instead.

Brenda Strong, David Shannon's sister, watched and wept as the 16-year-old entered her plea in court.

"It's really hard to look at somebody that was considered part of your family and to have her admit that she did this," she said. "In my mind, I knew she was capable."

The way prosecutors see it, Joan Shannon was after insurance money. They believe she gave Elizabeth Shannon the gun and badgered her until she finally committed the murder.

"She put the gun to the man who has raised her since she was four years old," Strong said. "[She] pulled the trigger, and when he didn't die quickly enough. She put it to his chest and pulled it again."

For pleading guilty, Elizabeth Shannon will spend 25 years in prison. She also agrees to testify in her mother's case, that has not yet gone to trial.

Strong said Joan Shannon has been living with her ever since she made bond. Apparently, Joan Shannon and her daughter do not even speak to each other anymore.