FlickrThis is the way most Boeing machinists register a complaint with management.Gino Augustus Turrella, a 47-year-old ex-Boeing machinist from Des Moines, was convicted on Friday for sending threatening e-mails to his former employer.According to prosecutors, Turrella’s beef began in 2004 after he was suspended for not complying with orders. When Turrella came back, co-workers noticed threatening graffiti on the walls of the men’s bathroom. Months later someone mailed the boss who suspended Turrella a single bullet.Turrella was eventually fired in 2005. Two years later, prosecutors say the threats began anew. Turrella is suspected of owning over 100 firearms. Which made his threat to “shoot everybody he sees” to a co-worker particularly chilling. Turrella also called in a bogus bomb threat to a Shell Oil refinery and threatened to strap himself with explosives in order to cause “maximum death and destruction.”For his 19 felony counts, Turrella faces anywhere between five to 10 years in prison. But considering the recent workplace massacres in Ft. Hood and Orlando, it wouldn’t be surprising to see him get the maximum.