For months, the Syrian born-attorney and manager of Hungarian gypsy violinist Janczy Rigo had become increasingly jealous of the influence that the performer's wife, Katherine Emerson Rigo, exercised over his own wife, Leonore. Though husband and wife often argued over the intensely emotional relationship existing between the women, Leonore continued to see Mrs. Rigo. On the night of November 3, 1908, some three weeks after Leonore had consulted an attorney regarding a divorce, Shibley fatally chloroformed his wife in the bedroom of their spacious apartment at 508 W. 122nd Street in New York City. The young attorney placed her body in bed, and spent the next few hours writing letters. Shibley waited until a servant fed their 2-year-old son and left the apartment to take the child for a walk before re-entering the bedroom. There, he laid next to his dead wife, slit an artery in his left arm above the elbow with a razor blade, stabbed himself near the throat, and covered their bodies with a sheet.
A handwritten letter to Leonore's sister found on the dining room table read: "Better this than her life as exampled by the past few months. Take care of baby. I could not take him. You see what I took it all in and said nothing." In another letter, unaddressed, Shibley issued a warning to American men:
"Maybe I am insane; maybe not. I have loved my wife with a love that passeth human understanding. Let the men of America get out of their lives the artificial life -- the restaurant life -- smoking, drinking, especially among women, and such things as this will never be. Breed in your little girls the love of home so that they may see, and breed their children when women. I am happy. No temptation can now reach my loved wife. No stage, no restaurant, no automobile that I cannot provide, but peace -- Goodbye, mother and brothers. By death I wipe out the sins of life. We prefer to be cremated or in one grave. This is only a parting. If men would only bring their wives to live within their means, and modestly, America would be a Paradise and each woman could not set another example. Oh, my people -- I am, the first of you, a murderer and a suicide! How the workd do burn! Forgive me!"
In a statement to The New York American, Leonore's sister blamed Mrs. Rigo for the tragedy: "I feel convinced that my sister's death must be laid at the door of Mrs. Rigo. The violinist's wife seemed to exercise a strange fascination over my sister. The luxurious manner in which Rigo's wife lived undoubtedly had an effect on Mrs. Shibley. She had been perfectly happy at first in marrying a man who was devoted to her, but after she met Mrs. Rigo she at once began to show a distaste for domestic duties. Mrs. Rigo initiated her into all the hollow enjoyments of suppers at midnight restaurants and automobile rides to out-of-town inns. All that was out of keeping with her home environment. While Mrs. Rigo denied that any "unusual relationship" existed between them, she did admit that she "seemed to exercise a fascination" over Leonore, adding, "But if she wished to admire me, why should I object?" Mrs. Rigo also maintained that Nassib Shibley himself was "insanely infatuated" with her, but "met with no response."