The penal code is based on the principle of nullum crimen sine lege (no crime without a law), but remains a tool for political control despite several amendments reducing ideological influence. Courts carry out legal procedures related to not only criminal and civil matters, but also political cases as well. Political prisoners are the only ones that have their entire family and themselves are sent to labor camps, while criminal offenders are incarcerated in correctional facilities and prisons. 
Article 157 of the Constitution states that "cases are heard in public, and the accused is guaranteed the right to a defense; hearings may be closed to the public as stipulated by law". The lack of judicial independence is also evidenced by Article 11 of the Prosecution Supervisory Law that stipulates "The prosecutor(s) shall supervise whether the trial or arbitration of a case is accurately deliberating and resolving the legal requirements and in a timely manner."
What are some of the amendments made to reduce the ideological influence on the North Korean judiciary? The article on the North Korean judiciary however mentions that it is not independent and that the party can influence the decisions made by the judiciary, but I don't think I understand the argument made, especially the second, because they seem to imply something rather indirectly. However, it does not relate to ideological influence only political influence.