A graduate of the Royal Dramatic Academy in London, Jerome acted on stage in China, but never appeared in films. On August 27, 1958, Jerome's ex-husband Edwin, became alarmed after the switchboard operator at the Hollywood apartment where the former actress lived informed him that her phone had been off the hook for several hours. Edwin Jerome entered the apartment at 1738 N. Las Palmas Avenue and found Helene's naked body in the rear, a victim of strangulation. Investigating officers found a screen torn away from a painted window which allowed the killer access to the apartment. A few days later, Edgar G. McAdoo, a 25-year-old carhop from Texas, was arrested on suspicion of murder due to his resemblance to a police sketch based on descriptions of witnesses who saw with the 50-year-old onetime actress in a bar shortly before her death. McAdoo admitted being with Jerome and to escorting her back to the apartment, but insisted he then left. The case against McAdoo collapsed due to a lack of physical evidence and his passing of a lie detector test.
Only momentarily deterred, authorities arrested Miller F. Dowdy, 42, on September 6, 1958. The operater of a newstand on Hollywood Boulevard only a block away from Jerome's apartment on N. Las Palmas, Dowdy admitted briefly dating the woman, but maintained he was at work on the day of the killing. As with McAdoo, the case against Dowdy soon fell apart. The Jerome murder remained a cold case until November 21, 1962, when Michael John Donahue, a 26-year-old shipping clerk from La Puente, California, walked into a Portland, Oregon police station and confessed to the strangulation. Guilt-stricken over the murder, he fled to Oregon to "try and get away from it all." Donahue pleaded guilty to second-degree murder and was sentenced in April 1963 to a prison term of 5 years to life.