WASHINGTON, Dec. 3 — Friends of Charles D. Riechers, whose Air Force career took him from the back of a B-52 cockpit to the front of the service’s $30 billion procurement office, said something was telling in the fact that his suicide note to his boss was typed. They described it as an effort to set the record straight by a meticulous man who felt deeply misunderstood.

“I first and foremost express my deepest regret for a situation based on my naïveté,” Mr. Riechers’s note read, according to a person familiar with it. “I’ve created a scandal.”

On Oct. 14, neighbors found the body of Mr. Riechers, a 47-year-old husband and father, in his garage in Loudoun County, Va., just outside Washington, dead apparently from the fumes of his car. Instead of clarity, though, Mr. Riechers’s last act cast a cloud of suspicion over the Air Force, threatening to plunge a service still struggling to emerge from one of its worst scandals into another quagmire.

Mr. Riechers, who was the second-highest-ranking official at the Air Force procurement office, had come under scrutiny by the Senate Armed Services Committee after a news report that said the Air Force had arranged for him to be paid by a private contractor during the two months he awaited White House approval for the job.