May I ask for a little more explanation on this? I thought that miracles had to be proved and attributed as occurring during life on earth to qualify for Sainthood. How is it proved and attributed that miracles are accomplished after a person's death?
A miracle that qualifies for sainthood is a miracle occuring after the death of the candidate saint, as a result of a prayer to him. The candidate saint then intercedes from Heaven and the Holy Ghost performs the miracle. The miracle has to be objectively verifiable, typically, a healing. No medical treatment must have been applied that could have been the cause of healing. Presently, many are praying to the late Pope John Paul for healing and there are reports of some possible situations under considerations, as there is a strong belief that he is a saint. At the same time, the fact that a sick person got healed after a blessing of the late Pope when he, the Pope, was alive, do not qualify.
There is also a requirement of martyrdom, sometimes waived. Since the late Pope did not die of his wound, it is not clear if he can be considered a martyr, although we now know tha the was in constant pain following the assassination attempt.