Background: When a criminal offence is committed by a single person, the problem of criminal responsibility is clear, whereas when the criminal offence is committed jointly by two or more people, the problem of responsibility is discussed. In this paper, the issues related to the problems of the responsibility of accomplices participating in a criminal activity will be addressed, such as the special subject, the excess of the executor, the cooperation and complicity of the case, the use of irresponsible persons in the commission of the criminal offence, and cooperation with unidentified persons. This article will answer the question of whether the criminal offence committed in cooperation would qualify in cases of cooperation with unidentified or irresponsible persons. The conclusions deal with the fact that if the criminal offence is carried out with the will, desire, and joint contribution, it is a product of the joint criminal behaviour, so the persons will be held accountable as accomplices. Also, collaborators are not responsible for other actions of the executor during the commission of the criminal offence, or for actions that go beyond the agreement. Albanian criminal law does not accept objective responsibility in the commission of a criminal offence, it also requires the subjective element. Regarding acceptance of cooperation, there is no cooperation with irresponsible persons. It would not be enough to prove only that in the commission of the crime other persons also participated, be they all adults, but it must be proven simultaneously that the unidentified persons are criminally responsible. Methods: In this study, a comprehensive legal analysis approach was employed to delve into the intricate issues surrounding the criminal responsibility of accomplices engaged in joint criminal activities. The methodology involved a meticulous examination of Albanian criminal law, jurisprudence, and relevant legal principles. The study focused on various aspects, including the special subject, the concept of cooperation, the excess of the executor, cooperation, complicity within specific cases, the utilisation of irresponsible individuals in the commission of criminal offences, and collaboration with unidentified persons. This method allows for gaining a profound understanding of the legal framework governing joint criminal behaviour and accomplice liability. Results and conclusions: The findings of the research shed light on the complex issues surrounding the criminal responsibility of accomplices in cases of joint criminal activities. Through an in-depth analysis of Albanian criminal law and jurisprudence, answers to critical questions concerning the qualification of criminal offences committed in cooperation, especially in cases involving unidentified or irresponsible persons, are provided. The results confirm that when a criminal offence is executed with the shared intent, desire, and joint contribution of individuals, it unequivocally constitutes joint criminal behaviour, leading to accountability for all involved accomplices. Furthermore, the research elucidates that collaborators cannot be held responsible for actions by the principal offender that exceed the scope of their agreement. Additionally, emphasis is given regarding Albanian criminal law adhering to a subjective element requirement for criminal responsibility, ruling out objective responsibility in the commission of criminal offences. Regarding the acceptance of cooperation, the findings underscore that the mere participation of other individuals in the commission of a crime, even if they are adults, does not establish criminal responsibility for unidentified persons. Instead, it necessitates the concurrent demonstration of their individual criminal liability. The results provide valuable insights into the legal principles governing the responsibility of accomplices in joint criminal activities within the Albanian legal context.