MacCreanor highlighted the evidence of a former partner of McCullagh who said he had assaulted her after seeing messages to another man on her phone in December 2019.
The prosecutor said that McCullagh said he struggled at Christmas due to deaths in his family.
He added: “Fast forward to December 2022. The prosecution don’t have to prove motive but this was Christmas, it was a partner and there were messages.”
He highlighted that McCullagh had the PIN for Natalie’s phone which contained messages with other men. Some of those messages were sexual in nature whilst others discussed potentially breaking up with McCullagh in the new year.
The prosecutor then spoke about CCTV footage of the person of interest travelling to and from Natalie’s home – ending in a taxi ride to McCullagh’s front door.
Referencing a photograph of McCullagh in a hat and wig found on Instagram he said the person of interest in CCTV had “adopted a look that he’d just happened to use”.
The jury was also reminded that McCullagh’s friend Anne had told the court that despite suggestions he only had two jackets he also owned a distinctive weatherproof coat that he’d bought in a thrift shop.
She provided the court with a photograph of him in this coat.
The prosecutor said: “There is a sequence to this that knits and ties together. It’s him, I have no doubt.”
McCullagh denies the charge against him.