What is meant by conditional justice in the witnesses for the execution of hudud punishments, and how can it be verified in the current era?

Justice in testimony means avoiding all major sins and generally refraining from minor sins, as well as avoiding permissible acts that compromise one's integrity (murū’ah). It is stipulated that a witness must be free and alert. A just person is one who avoids all major sins. The testimony of someone who frequents gatherings of immorality and revelry is not accepted, even if they do not commit the sin themselves. For justice, it is sufficient that nothing contrary to it is known about the person, for people are presumed to be just unless proven otherwise.