Maryna Zhytnyk-Kavaliauske and Alex Chernoff were both found dead in her home in South Farm Road, Worthing, on April 13 last year.
At Crawley Coroner's Court yesterday, assistant coroner Joanne Andrews concluded that Mrs Zhytnyk-Kavaliauske was unlawfully killed and that Chernoff took his own life.
The inquests heard that the police ruled out a number of other hypotheses, including a suicide pact, that the mother-of-two killed Chernoff and then herself, and that a third party killed them both.
DC Dawn Robertson from Sussex Police led the investigation. She said that by speaking to friends and family, officers had ruled out that the pair were in a relationship.
She said: "We couldn't find any hard evidence that suggested that Maryna had been in a relationship with Alex. Alex was obsessed with Maryna, but we never found any evidence to suggest she was in a relationship with him.
"She spoke incredibly highly of her husband and family, and how important that was to her."
DC Robertson said that Chernoff, a family friend who was helping to look after their children, had displayed 'strange behaviour' towards her in the run-up to their deaths.
She said: "Alex had cut up her clothing, cut telephone lines in her home address and turned up at her place of work, but Maryna was of the opinion that she wanted to protect him and look after him."
Her husband Giedrius Kavaliauskas was in Lithuania with their two children at the time of the deaths, and was at his wife's inquest. In a statement read out at the inquest, he said he believed Chernoff killed her.
He said: "She was a very forgiving, loving person and tried to give someone a chance and do their best for them.
"All she had done was try to help him."
"We were very happy together"
Mrs Zhytnyk-Kavaliauske, from Ukraine, and Mr Kavaliauskas, from Lithuania, first met when they were flower pickers at a farm in West Sussex. They got married and had two children together, who are now 12 and 9, and moved into their home in South Farm Road, Worthing in 2007.
He said: "We were very happy together and had a perfect relationship. We would share any problems and talk them through. She was very kind and thoughtful.”
The couple first met Chernoff, known by different names but to them as Viasa, in 2004 through his then-wife. They became close and asked him to be their daughter’s godfather.
In 2009, Mr Kavaliauskas got in trouble with the police and went to prison for four years. “Maryna stood by me and visited me every week,” he said.
By this time, Chernoff had split with his wife and had nowhere to live, so he moved into their home and helped Mrs Zhytnyk-Kavaliauske look after the children.
“I was not happy with this arrangement, but there was nothing I could do,” Mr Kavaliauskas said.
"I trusted her; she was only interested in family"
He believed it was at this point that Chernoff developed feelings for her. He added: “She only saw him as a friend. I trusted her; she was only interested in family.”
The breakup affected Chernoff’s mental health and led to him drinking excessively, the inquest heard.
When he came out of prison, Mr Kavaliauskas found a job as a HGV driver and was away from home a lot, so Chernoff was still needed to help around the house, he said.
They bought a flat in Salisbury Road, Worthing, and rented it out to him.
Chernoff was diagnosed with mental health problems and said he ‘was not made for work’ so relied on benefits - and Mr Kavaliauskas believed he was ‘playing the system’, he said.
According to Mr Kavaliauskas, Chernoff sent abusive messages via text and social media, and there was one occasion where he came to her workplace in Victoria Lodge Dementia Care Home in Shakespeare Road, Worthing, and shouted abuse at her and smashed a window or door there.
Mrs Zhytnyk-Kavaliauske reported him to the police a few times, including on November 22, 2017, the inquest heard.
What were the events leading up to the incident?
On Sunday, March 8, Mr Kavaliauskas flew with the children to Lithuania to see his family, but Mrs Zhytnyk-Kavaliauske had to stay behind as she had just started a new job and could not take holiday, the inquest heard. She saw her family off at the airport, which was the last time she saw them.
She was meant to pick up her brother Vitalie Jitnic from Gatwick Airport on April 12. But when she did not arrive, he contacted family member Ainious Greggaliulas and together they went to her home.
When they could not rouse anyone, they went to Chernoff's flat, but he was not in, so they returned to Mrs Zhytnyk-Kavaliauske's home and broke in through the patio doors before making the tragic discovery and calling the police.
The post-mortems for Mrs Zhytnyk-Kavaliauske and Chernoff found that they both died from hanging. Both had bruises and injuries consistent with a struggle, but it could not be confirmed whether these happened before or after their deaths, the inquests heard.
The inquest into Chernoff's death heard how he was being treated by his GP for depression, auditory hallucinations, alcohol problems, OCD and erectile dysfunction.
His internet search history on his laptop showed he was researching suicide days before their deaths, DC Robertson said.