BEAUMONT, Texas — Shamsud-Din Jabbar’s high school friends knew him as “Sham” — a good student with a quiet disposition and a bright future. He went on to become a model soldier in the Army, where his work ethic and attitude impressed his commander during a tour in Afghanistan. 

“He was a great soldier, someone who showed discipline and dedication,” the commander, Rich Groen, posted on social media. 

But over the past few years, as Jabbar worked to climb the corporate ladder,…