"- Elmer L. Irey"[Wilson] sweats ice water" - Suspect who was interrogated by Frank J. WilsonIn January 1929, an investigation conducted by Prohibition agents under Alexander Jamie (including Jamie's brother-in-law, Eliot Ness) into bootlegging in Chicago Heights uncovered evidence indicating that Al Capone's brother Ralph had not paid taxes on a sizable illegal income.The 1927 Supreme Court decision in "United States v. Sullivan" having already established that any criminal activities that yield an income are subject to income taxes, the Intelligence Unit of the Bureau of Internal Revenue headed by Elmer L. Irey began to build tax evasion cases against leading figures in the Chicago Outfit, with the ultimate goal of convicting Al Capone.