A paramedic who arrived at the North Carolina home of Jason Corbett on the night he was killed has said he was responding to an emergency call about a cardiac arrest.

Sergeant Barry Alphin was giving testimony at the trial of US woman Molly Martens-Corbett, 33, and her 67-year-old father Thomas Martens who are accused of killing Mr Corbett two years ago.

Both are charged with second degree murder for their role in causing the death of the 39-year-old at his home in Wallburg on 2 August 2015.

Sgt Alphin, a paramedic with Davidson County EMS, said that when he entered the bedroom of the house, the only light was provided by an overturned lamp and he was unable to turn on an overhead light.

He said he saw lots of blood.

"You don't expect to see that much blood", he said, adding that Mr Corbett showed no signs of life at any point at the scene.

The paramedic told the court that the decision was made to move Mr Corbett to the ambulance to better treat him and it was during this process that he realised there was heavy trauma to Mr Corbett’s head.

Corporal Clayton Dagenhardt, with the Davidson County Sherriff’s Office, told the court that when he arrived at the house he found Mr Martens inside with Ms Martens-Corbett and that Mr Martens was wearing a shirt and boxer shorts.

He said he and another detective, Cpl Rusty Ramsey, went to the bedrooms of Mr Corbett's children, Jack and Sarah, to move them downstairs to the basement and described how Sarah was apprehensive of going downstairs.

Cpl Dagenhardt said he asked her to close her eyes, to prevent her from seeing blood in the hallway, and carried her down the stairs and left her and her brother with Mr Marten’s wife, Sharon.

Another paramedic also gave evidence of her involvement in attempts to revive Mr Corbett.

Amanda Hackworth said she had asked how long Mr Corbett had "been down" before the emergency 911 call was made.

David Dillard, a former deputy with the Davidson County Sherriff’s Office said he escorted Ms Martens-Corbett to his patrol car.

He said she was wearing pyjamas and he did not observe any injuries on her.

He said she was "making crying noises" but he did not see any visible tears, and that she was seen rubbing her neck before she was brought to her neighbour's house.

The neighbour, David Firtzsche, said he considered Mr Corbett a friend and said his family and the Corbetts often got together with large groups from the neighbourhood for barbeques.

He said the two men played on a local YMCA soccer team together.

Mr Fritzsche said that the day before Mr Corbett's death, both men had cut their lawns and afterwards had several beers together that afternoon.

He said their wives and children joined them a little while later. He said that Sarah Corbett had left her boots in his yard and he returned them to the Corbett house some time later.

Mr Firtzsche said that Thomas Martens and his wife arrived at around 8.30pm.

When asked to describe Mr Corbett’s demeanour when he returned the shoes, Mr Fritzsche said he appeared normal and he "did not observe any signs of impairment".

He said that he got up at around 3.30am to go to the bathroom and saw emergency vehicles and flashing lights next door.

He remained in his house, but at around 5.30am, Ms Martens-Corbett arrived there.

He said he did not see any visible injury to her.