Soble himself was sentenced to a seven-year sentence, which he began serving at Lewisburg Prison. In 1958, Soble intentionally swallowed more than a pound of nuts and bolts, in what was characterized as a suicide attempt but which Soble later claimed was a protest against prison conditions. In 1961, Soble testified against his brother, despite attempts by Robert's attorney to have Soble declared mentally incompetent. Robert Soblen committed suicide in 1962, and shortly thereafter, Soble was released early for good behavior.