Re: Hell of a mail truck . . .
In many rural areas, a single person delivers the mail every day and may stay on the job for many years. People tend to know who is driving by and come to know their letter carrier personally. Strange cars (or mail trucks) would likely attract unwanted attention.
According to the news report, the suspect is "identified as Luke John Helder, whom the FBI described as a white male with dark hair and green eyes." He is believed to be "driving a gray or black 1992 Honda Accord with a Minnesota license plate bearing the number EZL 783".