Elias James Walker heard voices instructing him to kill his father, according to authorities.

In 2012, Walker stabbed his 45-year-old father in his sleep with a sword at a Mount Pleasant motel. He had endured years of verbal and physical abuse at the hands of his father, Anthony Walker, according to attorneys.

In a Charleston courtroom Friday, Elias Walker, who suffers from autism and psychosis, pleaded guilty but mentally ill to voluntary manslaughter and possession of a weapon in the commission of a violent crime.

The 23-year-old Mount Pleasant man had been originally charged with murder, but he accepted a negotiated plea from prosecutors that came with an 18-year prison sentence and five years of probation, which a judge accepted Friday.

The judge originally told Walker he would not be eligible for parole and would have to serve the full 18 years in prison, but now that matter is up for debate.

Parole question

Walker's attorney, Alicia Penn, argued that a state law allows Walker to be eligible for early parole.

Penn argued the law allows Walker to be paroled after serving one-fourth of his prison sentence if she can prove he was a victim of domestic violence at the hands of his father.

Walker's father physically and verbally abused Elias Walker throughout his life, according to Penn.

But there's another problem. The law states, in order to be eligible, Walker must have been the abusers' spouse or former spouse; that they shared a child in common, or that they were a male and female living together.

Ninth Circuit Solicitor Scarlett Wilson argued the statute does not apply in this case.

Penn said the law is unconstitutional because it should cover all children abused by that individual.

Since constitutionality is being questioned, Young said the S.C. attorney general must weigh in.

He also gave prosecutors and Walker's attorneys 10 days to file arguments.

Prior abuse

Vicki Bourus, a social worker and executive director of the Family Justice Center in Georgetown, testified during the hearing. She interviewed Walker and said he made statements that his father beat him and threatened his life on numerous occasions.

There also was evidence of abuse before the killing, according to prosecutors, who took the abuse into consideration when offering the plea agreement.

"I think this man has suffered almost every form of abuse chronologically over his lifetime that a person could endure," Bourus testified.

Anthony Walker also suffered from mental illness, according to Penn. He was paranoid and was convinced someone was trying to kill him, even reporting it to a police agency. Penn said Anthony Walker would hear voices in the middle of the night and leave the hotel.

"Tony's paranoias became Elias' paranoias," Penn said.

The crime

At around 1 a.m. Sept. 17, 2012, Walker used a sword to stab his father inside a room at the Fort Moultrie Motel on Stuart Engals Boulevard, which has since been torn down.

An autopsy revealed Anthony Walker suffered five chop wounds to the left side of his head and other abrasions on his body, according to Wilson.

Elias Walker initially told officers he had left the motel, where he and his father were living, to buy beer when someone must have attacked his father, according to prosecutors.

He later confessed to the slaying and admitted to waiting five to seven minutes after stabbing his father before calling 911, Wilson said.

Reach Natalie Caula Hauff at 937-5594 or Twitter.com/ncaula.