Is it permissible to use the term "martyr" for those who died treacherously and unjustly, such as the Al-Ahly club fans in Port Said, and does the hadith "He who is killed defending his own blood is a martyr" apply to them?

A Muslim who is wrongfully killed is hoped to be among the martyrs of the Hereafter and to receive their reward, due to the narrations indicating that the sword erases sins and that killing expiates sins. The Prophet, peace and blessings be upon him, bore witness to the martyrdom of Umar and Uthman, and they were both killed wrongfully. It is hoped that a specific individual will attain what Allah has promised, but one should not definitively assert that he is a martyr, because we do not judge a specific individual to be in Paradise or Hell unless revelation has decreed that for him.