John Barnett had worked for Boeing for 32 years, until his retirement in 2017.
In the days before his death, he had been giving evidence in a whistleblower lawsuit against the company.
Boeing said it was saddened to hear of Mr Barnett’s passing. The Charleston County coroner confirmed his death to the BBC on Monday.
It said the 62-year-old had died from a “self-inflicted” wound on 9 March and police were investigating.
Some parts of the USA already are, but in pockets. The USA is definitely an oligarchy at this point, but still not a complete autocracy, and there’s still a reasonable amount of trust that an actual investigation will be taking place regarding the circumstances of his death, which means not being able to hire just any sort of hitman for these stints.