Greenglass took no time in implicating his wife, Ruth, and his brother-in-law, Julius Rosenberg. As a result, Julius was arrested on 17 July 1950, and Ethel was arrested three weeks later, on 11 August 1950. Neither could post the $100,000 bail set at their initial hearings and they were incarcerated at the New York House of Detention, pending further investigations.
Julius and Ethel Rosenberg were charged with the crime of conspiracy to commit espionage and tried under the Espionage Act of 1917. It was claimed that, as a direct result of the Rosenberg Spy Ring, the Soviets had gained the expertise to manufacture atomic bombs years earlier than would otherwise have been the case.