Daniel Jack Kelsall has been found guilty of the stabbing murder of Sydney businessman Morgan Huxley in his Neutral Bay apartment in September 2013.

The jury also found 22-year-old Kelsall guilty of indecently assaulting the 31-year-old man.

There were gasps from the public gallery when the verdict was read out, but Kelsall showed no emotion.

The jury heard almost two weeks of evidence including allegations that Kelsall's DNA was found on Mr Huxley's body.

Earlier, the trial heard Kelsall followed Mr Huxley to his home in the early hours of September 8, 2013 and let himself in before indecently assaulting and stabbing Mr Huxley 20 times.

Kelsall, who pleaded not guilty to murder and indecent assault, told the jury he had a consensual sexual encounter with Mr Huxley who was assaulted by an intruder.

Judge Robert Allan Hulme said the sentencing hearing would be on April 29.

Life taken by 'worthless psychopath'

Jessica Hall, the ex-girlfriend of Morgan Huxley, called his killer a "worthless psychopath". ( AAP: Dan Himbrechts )

Mr Huxley's ex-girlfriend Jessica Hall said he was a loving and inspiring man.

"Morgan was beginning to make his way in the world, he had hopes and dreams that he will never be able to realise," Ms Hall said outside the court.

"He will never get married and never enjoy running around a park with his children.

"His life was stolen by a worthless psychopath."

Earlier in the week, Kelsall took the stand of his murder trial to deny stalking and fatally stabbing Mr Huxley.

He told the court while he did not follow Mr Huxley home from the Oaks Hotel at Neutral Bay on the night of the murder, he did strike up a conversation with him while waiting to cross the road at a set of lights.

Kelsall said on Monday: "I then asked him how his week had been. He'd been smiling ... and then he lost his smile a bit and he said he'd had a stressful week."

The Defence argued Mr Huxley took up an offer from Kelsall to talk about it and invited him back to his place.

Kelsall is accused of indecently assaulting and stabbing Morgan Huxley 20 times in his Neutral Bay unit. ( Supplied: Facebook )

Kelsall previously said that during a consensual sexual encounter in Mr Huxley's bedroom, "something" struck him and he realised there was at least one other person in the room who started fighting with Mr Huxley.

"It looked like this other person and Mr Huxley were fighting," Kelsall said.

Kelsall said he then ran out of the apartment and back to his home, which was also in Neutral Bay.

He admitted not telling his parents and lying when questioned by police because he was scared and was trying to distance himself from what happened.

Crown prosecutor Peter McGrath SC suggested Kelsall did not tell anyone this version at the time because he made the story up at a later date.

The trial previously heard Kelsall told a GP and a psychiatrist that he was having "intrusive thoughts" about killing someone on his way home from work, about 16 months before the murder.

The trial also heard Kelsall was captured on CCTV footage carrying a bag that was later found to have blood stains that belonged to Mr Huxley.

The court heard the killer was most likely to have been wearing the bag at the time of the stabbing.

Detective Sergeant Gregory Moon from the Forensic Services Group told the jury he considered a range of scenarios but "the wearing of the bag was the highest probability".