Vilson Meshi, who was living in Glossop, was asleep in the back of his Audi outside his former partner’s house in Essex where he went to visit two of his children.
His former partner reported him missing the following day, February 27, when he failed to arrive at the house or respond to calls and text messages.
She also told police about an Audi, which was in her usual parking space. She did not recognise it as Mr Meshi’s car, but was concerned as it had blacked out windows and the passenger door was locked but ajar.
When police and firefighters attended, Mr Meshi was found deceased in the back of the car.
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A post mortem examination later found he had died as a result of inhaling fire fumes.
The remnants of a hand-held flare were found inside the car and in a nearby alleyway. Flares of the same make and model were reported stolen a week earlier from a boat docked at Wat Tyler Park in Pitsea, Essex.
Keani Hobbs, 18, a student, of Stagden Cross, Pitsea, and a 16-year-old boy from Camberwell, London – who cannot be identified for legal reasons - were arrested and later charged with Mr Meshi’s manslaughter and theft of the flares.
Both were convicted by a jury on Thursday Thursday, August 24, of both charges following a trial that began at Basildon Crown Court on July 31.
Hobbs was sentenced Friday, August 25 to nine years for manslaughter and 12 months for theft, to run concurrently.
Her co-defendant was sentenced to six years for manslaughter and 12 months for theft, to run concurrently.
Detective Chief Inspector Stephen Jennings, of the Kent and Essex Serious Crime Directorate, said: “I believe the correct verdicts have been given in this case. The defendants acted recklessly and were it not for their thoughtless actions, Vilson would not have needlessly died.
“I want to thank his family for working with us during this very difficult time and pay tribute to them for their dignity and restraint.
“While nothing will bring Vilson back, I hope these convictions and sentences are of some comfort to them and they can move forward to start rebuilding their lives.”