Back in the late 1950's my next door neighbor was a man named Steve Guthery (Guthrey?). He claimed to be the ex-sheriff of Dallas County, Texas. He told me that he left Dallas to protect his family because his restaurant and home were firebombed by the "mob" in Dallas. He specifically named Jack Ruby, who he claimed was awarded the Dallas territory by the Chicago mob as a reward for his loyal service as Jimmy Hoffa's Teamster Union secretary.
At the time, I had never heard of JFK and of course, he was only beginning his run for the presidency. I have no way to verify the conversation, but I'll bet that someone from Dallas would be able to find out if, in fact Steve Guthrey (sp?) was the sheriff of Dallas in the 1950's and if the story he told me was credible.