THE Charleston Coroner's Office released its determination in the headline-inducing death of John Barnett, a former Boeing quality inspector who was found dead after he did not show up for the second day of deposition.

The most compelling evidence is video footage that the Charleston County Coroner Bobbi Jo O'Neal said shows no one approached Mr Barnett's vehicle after he backed into a parking spot the night before he was found dead inside his vehicle.

The coroner's report, published by Fox News, indicates that investigators believe Mr Barnett died of a single, self-inflicted gunshot wound to the head, reports The Dallas Express.

The report states that Mr Barnett had gunpowder residue on his right hand, which was holding a Smith & Wesson handgun when he was discovered by hotel staff.

The report and the publication of images purporting to be a suicide note have not quelled conspiracy theories in the matter. A friend of Mr Barnett, who has only been identified as "Jennifer," said that Barnett had told her in February that "If I end up dead, it wasn't suicide."

Mr Barnett was in South Carolina for a deposition by his own attorneys connected to claims that Boeing knowingly and wilfully suppressed knowledge of quality control issues.

Boeing has been under federal scrutiny since a door plug blew out of an Alaska Airlines flight in January. The incident did not result in casualties but came just three days before the airline manufacturer would have been released from legal responsibility for the deaths of nearly 400 people in two crashes in 2018 and 2019.

The cause of those crashes was determined to be a faulty flight control system that put the company's 737 Max 9 aircraft into a nose-down dive that pilots could not avert. Boeing knew about the problem but concealed it from federal investigators prior to the crashes. The deferred prosecution agreement allowed the company an opportunity to rectify manufacturing defects and a lack of quality control that led to the crashes.

Mr Barnett was one of several employees to report to the Federal Aviation Administration that the company was taking shortcuts to improve productivity and enhance stockholder confidence.

Attorneys representing Barnett are now claiming that despite the fact Boeing seemingly did not pull the trigger on the gun, the company is responsible for his death.

The attorneys allege that the stress and pressure placed on their client contributed to exacerbating preexisting conditions that led to his suicide.