William Kydd, 54,of Gabriel Close, Feltham, was convicted of the murder of 74-year-old Carole Harrison on Tuesday, 18 June following a trial at the Old Bailey.
He will be sentenced at the same court on a date to be set.
The court heard that police, the London Fire Brigade and the London Ambulance Service were called to reports of a fire at a residential address in Mays Road, Teddington at around 1am on Tuesday, 21 August 2018.
The body of a woman, later identified as Carole Harrison , was found. She was pronounced dead at the scene.
A post-mortem examination gave the cause of death as smoke inhalation and a head injury.
Carole, a mother of five and a former nurse, had lived in Teddington for 46 years, the last 18 of which were on her own since the death of her husband.
A murder investigation was launched after enquiries by LFB concluded that the fire had been started deliberately.
Detectives established that Carole had been seen in the company of a man of scruffy appearance on the day of her murder and shortly before the house was discovered ablaze. The man was subsequently identified as William Kydd,
Kydd was arrested on suspicion of murder on Saturday, 25 August 2018 and denied having had any involvement, answering ‘no comment’ to all questions put to him. He was released on bail.
Detectives continued to work on the investigation and began piecing together evidence of his presence at the scene.
A pathology report in November 2018 stated that Carole had been alive during the fire and had been assaulted shortly before it.
It was established that the fires had been started in four separate areas of the house and that internal doors had been closed; Carole would not have been able to close the doors owing to the arthritis she suffered.
Kydd was further seen on CCTV leaving Carole’s house minutes before the fire was first reported.
Forensic evidence found that Kydd had access to the address on the day in question and that, as a smoker, he had access to some form of ignition in order to smoke his cigarettes.
Mobile phone evidence showed that despite having been in near daily phone contact with Carole prior to her death, he made no attempt to call her after her murder and re-located to another area of London.
Kydd was re-arrested on Wednesday, 28 November 2018 and was charged with murder on Thursday, 29 November and remanded in custody.
Detective Inspector Domenica Catino, who led the investigation, said: “Carole was an elderly vulnerable woman who had a very trusting nature and would believe that as soon as she was spoken to by anyone they were her friends and she would go to any lengths to help them.
“Kydd clearly preyed on this vulnerability callously taking full advantage of Carole’s generosity for his own selfish gain and stopping at nothing to get what he wanted.
“On the night of her murder he violently assaulted Carole leaving her unconscious with a head injury. He then decided to set fire to the premises to cover up his actions and deliberately set fire to four areas within her home, in her bedroom where she lay by the doorway, the stairs and two separate downstairs rooms. As a result, there was no possibility, if Carole had regained consciousness, that she could have escaped.
“One way or another Kydd was determined to get rid of any evidence, which also included Carole, giving no thought to anything but himself.
“Kydd is an extremely dangerous individual who accepts no responsibility for his actions. It is always someone else’s fault.
“My thoughts go out to Carole’s family who were dignified throughout the trial and having to deal with Kydd’s antics in court which again displayed any lack of remorse. Frankly he did not care. I want to thank Carole’s family for their support and praise the good work of the investigation team in getting justice for Carole.”