In the United States v. Knight case of 1948, the Supreme Court dealt with issues related to tax evasion and fraud. The defendant, Mr. Knight, was charged with attempting to evade income taxes by falsely declaring his earnings for several years in a row. He argued that he had not committed fraud because he believed that his actions were legal based on advice from his lawyer and accountant who told him it was permissible to deduct certain business expenses before calculating net income for tax purposes. However, the court ruled against him stating that ignorance of law is no excuse for breaking it; hence one cannot claim innocence based on wrong advice received about what constitutes lawful behavior or not. The court also clarified an important point regarding criminal intent in such cases: even if someone genuinely believes they are acting within their rights due to incorrect information given by professionals like lawyers or accountants, this does not absolve them from guilt if their actions are found illegal under existing laws. This ruling underscored two key principles - firstly, every citizen has a responsibility towards understanding and complying with laws irrespective of any misleading professional guidance they may receive; secondly, courts will always consider whether there's evidence showing deliberate intention behind fraudulent activities when deciding upon convictions in tax evasion cases.

In the dissenting opinion for United States v. Knight, Justice Jackson disagreed with the majority's decision to uphold a lower court ruling that dismissed an indictment against Knight on grounds of double jeopardy. He argued that the Fifth Amendment protection against double jeopardy should not apply in this case because it was not clear whether Knight had been acquitted or convicted at his first trial due to a procedural error by the judge. According to Justice Jackson, allowing such errors to result in automatic acquittals would undermine public confidence in judicial proceedings and encourage manipulation of legal procedures by defendants seeking immunity from prosecution. Furthermore, he contended that dismissing indictments based on ambiguous verdicts could prevent justice from being served if defendants were indeed guilty as charged.