During World War II, Ruby's sister, Eva Grant, visited Dallas. Having operated a restaurant on the west coast, and considering it a lucrative business, she arranged, near the end of 1945, to lease a building under construction in Dallas, which she ran as a night-club. Part of the financing for this establishment, the Singapore Supper Club, was provided by her brothers. Jack Ruby, who apparently obtained the money from Earl Products, sent $1,100 as a down-payment on the lease, Earl contributed about $1,500, and Hyman paid for more than $2,000 worth of equipment.
Before she opened the Singapore in 1947, Eva Grant engaged in the sale of metal products. In that year she met Paul Roland Jones, who allegedly was seeking customers for iron pipe and whom she referred to Hyman Rubenstein. Jones had, at about that time, been convicted of attempting to bribe the newly elected sheriff of Dallas. On October 24, 1947, he was arrested for violating Federal narcotics statutes. Jack Ruby had visited Dallas early in 1947 to help Eva Grant manage the Singapore, and 5 days after Jones' arrest, Jack and Hyman Rubenstein were interrogated in Chicago by agents of the Bureau of Narcotics. The brothers admitted knowing Jones but denied awareness of his connection with narcotics. During the 2 years in which Jones was appealing his conviction he and other criminals frequented the Singapore Club, then operated by Jack Ruby.
Intensive investigation to determine whether Jack Ruby was criminally or otherwise connected with Jones' narcotics violation leads the Commission to conclude Ruby probably was not involved. A search of the files of the Bureau of Narcotics disclosed no record that either Hyman or Jack had been prosecuted by Federal authorities in 1947. Jack, Hyman, and Eva denied participating in any narcotics activities. Jones and his coconspirators also denied that Jack was a participant. One of Jones' confederates reported after the shooting of Oswald that although Jones "propositioned" the two brothers concerning narcotics, they refused to participate. Moreover, when one of the conspirators was arrested with 48 pounds of raw opium in his possession, he implicated Jones and another person, both of whom were convicted, but he did not implicate Jack Ruby or his brother.
Late in 1947, Ruby established permanent residence in Dallas. Shortly after shooting Oswald, Ruby stated that he returned to Dallas at Eva Grant's request, to help her operate the Singapore Supper Club. However, on December 21, 1963, he reported that although association with his sister had been the purport of his initial visit to Dallas, he returned there because of the failure of his "merchandising deals" in Chicago. These factors, in conjunction with his separation from Earl Products, probably motivated Ruby's move to Dallas.
A different reason has been given by Steve Guthrie, former sheriff of Dallas. Guthrie reported that shortly after his election as sheriff in July 1946, Paul Roland Jones, representing other Chicago criminals, offered him a substantial amount of money to permit them to move in and manage illegal activities in Dallas. Although he never met Ruby, Guthrie asserted that these criminals frequently mentioned that Ruby would operate a "fabulous" restaurant as a front for gambling activities.
Despite its source, the Commission finds it difficult to accept this report. A member of the Dallas Police Department, Lt. George E. Butler, who was present during virtually all the conversations between Guthrie and Jones and who performed considerable investigative work on the case, stated that Ruby was not involved in the bribery attempt and that he had not heard of Ruby until the investigation and trial of Jones had been completed. He explained that Ruby's connection with the case stemmed from the fact that, as mentioned previously, Jones and other criminals frequented the Singapore Supper Club. And 22 recordings of the conversations between Guthrie, Butler, and Jones not only fail to mention Ruby, but indicate that Jones was to bring from outside the Dallas area only one confederate, who was not to be Jewish.
Sometime in 1947, Jack Ruby's brothers Earl and Sam, pursuant to a joint understanding, legally changed their names from Rubenstein to Ruby. Earl testified that he changed his name because everyone called him Ruby and because a former employer advised him that it was preferable not to use a "Jewish name" on mail orders for Earl Products.
On December 30, 1947, Jack changed his name to Jack L. Ruby by securing a decree from the 68th Judicial District Court of Dallas. His petition alleged that he sought the change because the name Rubenstein was misunderstood and too long and because he was "well known" as Jack L. Ruby. The Bureau of Narcotics report of his relationship with Paul Roland Jones indicates that as of October 29, 1947, Jack was known as Ruby; however, several persons in Dallas knew him as Rubenstein.
Source: Warren Commission Report