It was no secret how much Steven Clayton "adored" his wife Lana Sue, so when she "accidentally" shot him in the head with a crossbow two years ago as he slept, nobody had any reason to doubt her.

The 64-year-old, who survived the bizarre incident with a relatively minor flesh wound, convinced detectives Lana Clayton's actions were entirely unintentional and likely connected to her chronic sleeping disorder.

But when Mr Clayton was found dead at the couple's lakefront South Carolina mansion on July 21, police decided to take a closer look, news.com.au reported.

Ms Clayton told deputies her husband had been suffering from vertigo for days before she found him lying facedown at the foot of the foyer stairs.

Advertisement

Over the next few weeks, the 52-year-old nurse played the role of a grieving wife and the couple's devastated friends gathered around the "sweet lady" to support her in any way they could.

Lana Sue Clayton with one of the couple's Italian Greyhounds. Photo / Facebook
Lana Sue Clayton with one of the couple's Italian Greyhounds. Photo / Facebook

The funeral was held in August in the backyard of the couple's enormous home — a replica of George Washington's famous Mt Vernon residence lovingly restored by Mr Clayton at great cost — in the upscale neighbourhood of Clover.

Meanwhile, police had been quietly investigating the couple's relationship and last week, they got the break they were looking for.

The toxicology had come back with an unusual result — the dead man's blood contained fatal levels of tetrahydrozoline, an ingredient in over-the-counter eyedrops that whitens red eyes.

The chemical is also found in nasal sprays but can cause seizures, stop breathing and induce comas even in small amounts if swallowed, according to the US National Library of Medicine.

Police documents obtained by the Charlotte Observer state that when investigators confronted Ms Clayton with the toxicology results she confessed to murder.

On Friday she was arrested and charged with homicide and malicious tampering of food.

Prosecutors will allege she poisoned her husband's water with tetrahydrozoline from July 19 until his death on July 21.

Advertisement

Ms Clayton is yet to enter a formal plea to the charges and has been remanded in custody. If convicted she faces the death penalty.

Lana Sue Clayton, 52, in her police mug shot following her arrest on Friday. Photo / York County Sheriff's Office
Lana Sue Clayton, 52, in her police mug shot following her arrest on Friday. Photo / York County Sheriff's Office

The distraught family of Mr Clayton told WSOC-TV they were "shocked and mortified at the cause of his death".

"All of our family and friends know how much he loved his wife, Lana, and how devoted he was to her. We are all still trying to process this," they said in a statement.

The couple had been together for eight years. Ms Clayton regularly attended a neighbourhood bible study group while her husband was known for his "big personality".

Ken Sanford, who knew both of them, told reporters he was still trying to digest the news of Ms Clayton's confession.

"I am just stunned," he told The Herald.

"She seemed like a sweet lady," Mr Sanford said. "Steven was very proud of her accomplishments."

Police have not released a motive but according to The Herald, Ms Clayton posted a comment on social media in March 2010 claiming her husband had been unfaithful to her.

"My husband is not a drunk, he had an affair. However, he is the father of my children and my kids look at my Facebook. I do appreciate the support though," she wrote.

Ms Clayton's Facebook account has since been deleted.

Prosecutors say they are now reviewing the crossbow incident, a process which may result in additional charges against Ms Clayton.

Steven Clayton, 64, was shot in the head with a crossbow by his wife in 2016 as he slept in the couple's bed but survived. Photo / Facebook
Steven Clayton, 64, was shot in the head with a crossbow by his wife in 2016 as he slept in the couple's bed but survived. Photo / Facebook

On May 30, 2016, Ms Clayton went to the York County Sheriff's Office to tell deputies that she had shot her husband earlier that morning, an incident report states, according to the Charlotte Observer.

She told officers she was downstairs in the couple's home "trying to load a crossbow" and was having difficulty with it. She said she went to the upstairs bedroom where Mr Clayton was sleeping and the crossbow "accidentally" went off, firing an arrow into the back of his head.

"She said he woke up yelling and bleeding from the wound," the report states.

After taking her statement, detectives went to the couple's home to investigate.

Mr Clayton told officers "he was fine and the shooting was accidental", adding that his wife suffered from insomnia and sleepwalking.

In a follow up interview on the crossbow incident, investigators found Ms Clayton at home "crying and upset".

She told them her husband was mentally abusive to her, and had "mood swings" but never physically hurt her.

In May 2017 detectives ruled the incident an "accident", concluding "no intent to commit a crime was found".

Prosecutor Kevin Brackett said that decision was now under review.

"We are making a comprehensive review of all events in the relationship between the defendant and the victim," he said.

"We will be taking a look at the relationship and the 2016 incident."

Before his death, Mr Clayton appointed his wife executor of his multimillion-dollar estate. The property is now the subject of legal action in the York County Probate Court.

Ms Clayton remains in custody and her next court date is yet to be determined.