A ‘sexually obsessed' killer smirked and flicked his hair as he was today found guilty of murdering his 19-year-old stepdaughter at her university accommodation.

Nathan Owens, 34, strangled Carla Georgescu after driving more than 100 miles through the night to her student halls in Preston, Lancashire, in February.

The depraved 'coward' remained silent throughout his police interviews and refused to give evidence in court, enabling him to dodge being cross-examined.

He then shocked onlookers by smiling and laughing from his seat in the glass-panelled dock while the grotesque details of Carla's killing were spelt out during his three-week trial. 

Having grown a full set of hair since his arrest, Owens sat in the dock with his legs casually crossed and his arms across his stomach as the verdicts were announced - pulling a face when he was found guilty. 

Jurors convicted him of murdering Carla after deliberating for just over three hours. He will be sentenced on Friday.

While exactly what happened in the early hours of February 4 may never be revealed, prosecutors suggested he was motivated by 'sexual jealousy'.

Owens had learnt that Carla - a second-year clinical psychology student - was planning a trip to her native Romania to meet a man she had been romantically involved with online, prosecutors had claimed.

A talented artist, Carla - who had moved to UK while she was still at school - was described as 'intelligent, gentle and articulate’.

Owens hid his secret depravity after marrying her mother, Janina.

But his trial heard how his 'escalating fascination' with Carla included having sex with a life-sized 'effigy' of his teenage stepdaughter which he had clothed in her nightdress.

A day before Carla was due to travel, Owens duped her into letting him into her student flat at 4am.

His intention was ‘to satisfy his sexual needs, come what may’, prosecutor Nicholas Lumley KC said in his closing speech at Preston Crown Court.

As he listened in silence, Mr Lumley asked whether Owens had treated Carla ‘like a doll, like one of your effigies’ before killing her when she ‘dared to say no’ to him.

Police initially suspected Carla’s death was suicide after her body was found slumped against a wardrobe door with a belt around her neck on February 5.

The horrific reality was revealed by CCTV which proved the account Owens later gave police that his wife Janina accompanied him in the early hours of the previous day to be a lie.

In addition, damning evidence provided by his modern car’s GPS system revealed how he had stopped on the way home to dispose of crucial evidence.

Arriving home to Hartlepool shortly after 8am on February 4, Owens did not tell his psychotherapist wife that he had been to see her daughter.

She became worried when Carla did not respond to her messages and phone calls.

The following day – which would have been Carla's 20th birthday – she contacted university security.

They carried out a welfare check and discovered her body.

Police broke the news to the couple, with Carla’s death initially put down to suicide.

Yet within hours, Owens was carrying out web searches about how police investigate suspicious deaths and wiping his electronic devices.

He later gave Mrs Georgescu a false story about having gone to Preston that night because Carla had wanted him to take incontinence pants to her and help her tidy her room.

When police started to become suspicious, Owens lied that he and his wife had been to see Carla together.

But CCTV footage revealed he had travelled there and back alone.

A clip played to the trial shows Carla – wearing a fluffy dressing gown and pyjamas – letting Owens into Ribble Hall, her block of student flats at the University of Lancashire, at around 4am on February 4, his head hidden by a patterned blanket.

He was captured leaving the building around an hour-and-a-half later, 'shielding' himself with an umbrella and wearing a face-mask while wearing Carla's trainers and carrying two bags.

Following his arrest, detectives were able to piece together his movements after the murder by downloading telematics information from the couple’s Ford Puma.

It pinpointed exactly where he stopped during the journey home, with searches of the surrounding area revealing Carla’s discarded mobile phone, her bloodied bedding and a blood-stained T-shirt.

Mrs Georgescu had last seen Carla three days before her death during an early birthday celebration at a Korean restaurant in Preston.

She had travelled from Hartlepool by train for the meal where they were later joined by Owens, who came by car.

Footage shows Owens and Carla both looking uncomfortable and staring at their phones after being left alone at the table during dinner.

Owens had become 'sexually fixated' with Carla, prosecutors alleged, secretly taking pictures of her dressed in her underwear.

His ‘depraved’ actions included having sex with an ‘effigy’ of Carla as well as her dolls and toys, and manipulating an innocent image of her so it appeared sexual.

But his 'dark life' was hidden from his wife, who had no idea he was staying up all night obsessing over Carla, the trial heard.

Owens was also convicted of grievous bodily harm with intent.

After the verdicts, Detective Inspector Pete Macdonald, of Lancashire Police, said: 'Carla was a young woman with her whole life ahead of her, a life that was taken away by someone she should have been able to trust.

'Owens had a despicable, perverted sexual obsession with his stepdaughter, an obsession that ended with him killing her. He has now been brought to justice for his crimes.

'No verdict brings Carla back, but I hope that her mum and the rest of her loved ones can feel some sense of justice that the man responsible for taking her future away has been brought to justice.'

He will be sentenced on Friday.