There was no question what happened one night back in April 2009 in a Houston, Texas suburb when a 12 year-old girl walked into her father's bedroom and shot him while he slept.

But after a jury deliberated for four day they acquitted the girl of murder charges Monday, and now her grandmother says she is in fear of her life.

During the three week trial the defense team for the girl, who is now 15, said that earlier that night in 2009 her father Mark Nelson was watching her bathe, and that she had asked him to leave the bathroom. She told authorities that her father warned her darkly that she would regret that demand.

The defense attorneys argued that after years of both sexual and physically abuse, the girl now feared for her life. So, she took her father's .38 caliber revolver and shot him.

The prosecution contended that Nelson's death was cold blooded murder and that his daughter did it because her father was too strict. They argued that if it was self-defense, the girl should have reported the alleged abuse before or even after the murder.

Houston psychiatrist and expert witness for the defense, Dr. George Glass, testified that it's not uncommon for a child to lie about physical and sexual abuse.

The girl, who is not being named because she is a minor and allegedly a victim of sexual assault, could have been sentenced to 40 years in prison if convicted of murder.

"We just looked at the evidence. The evidence was what brought us to the decision of self defense," juror Yvette Cardenas told ABC News affiliate KTRK.

The girl was released to her mother.

"I was excited. I was scared, very scary. I get to take her home. I'm OK," said the girl's mother, Miranda Jackson.

Mark Nelson's mother does not feel the same way. The girl's paternal grandmother says she now fears for her own life now that her granddaughter has been acquitted.

"She's been set free so she can do whatever she wants on the streets," Leona Nelson said to KTRK. "That was the best defense in the world for a little girl to accuse your father of abusing you, because people do not want to believe that a 12-year-old child would go in there and kill her father unless he abused her."

The teenager looks to move forward with her life, and is taking advanced placement classes at a high school. After the verdict, she told KTRK that maybe a career as an attorney is in her future.