SAN DIEGO (CBS 8) - The retrial resumed Monday for a North County woman accused of fatally shooting her husband.

Julie Harper is charged with second-degree murder for the 2012 death of her husband Jason Harper who was a teacher at Carlsbad High School. She was acquitted of first-degree murder last year.

[Jury selection begins in Julie Harper retrial

Harper claims that she shot her husband in self-defense, fearing that he would kill or rape her.

During Monday's hearing, both Harper's nine-year old daughter and eleven-year old son testified for the prosecution.

"I don’t remember much," said the boy. 

Harper's son was eight years old when his father was killed and he says his memory of the incident isn’t too clear. Prosecutors played back video recordings of the children being interviewed the day after their father's death for the jury.

"We heard a big thud," said the defendant’s son. 

Former litigator Ken Klein is a professor at California Western School of Law in San Diego, and he said that any time the prosecution puts young children on the stand, there are inherent risks. 

Prosecutors say Julie Harper shot and killed her husband of ten years in the master bedroom of their Carlsbad home while their three children watched television downstairs.

"They are subject to all the tugs and pulls of having to weigh between mom and dad. They are compelling. They are sympathetic, but they also may be less reliable in their memory and their ability to understand what they saw, and their ability to describe what they saw," said professor Klein. 

Klein also said that a challenge for the prosecution is how they jury views their move to put the children on the stand. 

"Three years may not sound like a lot to you and me, but for a nine-year-old, it is a third of their life, so can they really remember what they thing they remember," said Klein. 

According to Klein, the prosecution could be perceived as trying to use children to manipulate the case or trying to take advantage of them. 

Putting children on the witness stand can also be risky for the defense, said professor Klein. 

The defense has to probe the accuracy of their testimony, but at the same time not appear overly aggressive in the line of questioning. 

All three of Harper’s children currently live with their paternal grandparents in Los Angeles.

Jason's brother Brian Harper also testified in court. He said that his brother was not a violent man and told prosecutors that he missed him every day, before breaking down in tears while on the stand.

If convicted of second-degree murder, Julie Harper would face forty-years to life in prison. The jury can also consider the chargers of voluntary and involuntary manslaughter.