LOUISBURG, N.C. -

A Franklin County man who admitted to stabbing his 14-year-old sister to death and stabbing his mother was back home on Thursday after state psychiatrists found he committed the crimes while he was sleepwalking.

In January 2010, Joseph Bravio Mendez was accused of stabbing his mother, Lydia Etanislao, about 20 times while she was sleeping and stabbing and killing his sister, Julianna Mathews.

Mendez, then 18, was charged with murder.

"All of a sudden, I felt a sharp pain and when I looked, I saw him attacking me," Etanislao said Thursday.

After months of testing, Mendez's mother says it became clear he had no memory of the attack. In court, a psychiatrist for the state testified Mendez had been sleepwalking during the stabbings.

"This was a very unique case in that the state's own psychiatrist came to the conclusion that this was a sleepwalking case," Mendez's attorney Boyd Sturges said.

Mendez pleaded guilty to involuntary manslaughter and assault. He was given credit for time served.

Though disappointed with the outcome, Franklin County Assistant District Attorney Annette Sellars said with the state's two main witnesses both saying Mendez did not know what he was doing, it would be tough to get a first-degree murder conviction.

"The thing that people don't need to lose sight of is that Joseph is extremely sad," Sturges said.

Etanislao said she knew there was something wrong with her son. "Him doing this on his own, he would have never done that," she said.

Mendez is on probation for the next three years and must continue to have mental health evaluations. His family said he is now on medication for depression.

Etanislao said it is great to have her son home.

"I feel so happy that he's home," she said.

Photo courtesy: WRAL