The court also heard from a police constable who arrested and cautioned McCullagh, who was present when emergency services attended the scene.
Footage from his body worn camera was shown to the court. Upon his arrest for suspicion of murder and following his caution, McCullagh could be heard saying: “Murder – why?”
The second day of the murder trial also heard from a police sergeant said he attended the scene following a 999 call.
The sergeant told the court Natalie was found lying on the first floor, with her head in the living room and her feet protruding into the hallway.
“There was blood visible around her neck. I noticed a puncture wound,” he said.
He said he also saw a silver dog bowl, close to Natalie’s head, which “looked like it had been used to collect blood”.
He said that from his vantage point from the top of the stairs, he saw a black-handled knife.
Close to that, he said, he saw “some blood on the lower part of the wall – about a foot up”.
The trial continues.