I was reading "I'll Do My Own Damn Killin" by Gary W. Sleeper when I noticed this passage discussing a 1951 Fort Worth grand jury:

"Even without Binion's testimony, the grand jury developed a clear picture of Fort Worth gambling and official payoffs. The Kefauver Commission helped put the final piece of the puzzle in place when its investigators supplied the Tarrant County grand jury with records of a Chicago gambling equipment manufacturer, complete with invoices for sales and shipments to Fort Worth gamblers"