On the evening of Oct. 31, 25-year-old Fukuoka native Kyota Hattori — wearing makeup and a purple and green ensemble to emulate the villainous Joker of “Batman” franchise fame — boarded a Keio Line train at Keio-Hachioji Station, heading for central Tokyo. After spending half an hour meandering around Shibuya, which was packed with costumed revelers feting Halloween, Hattori headed back toward Hachioji, but reversed direction again at Chofu, where he changed to a Shinjuku-bound limited express train.

Soon after the doors closed, according to eye witness reports, he removed a survival knife and liquids from a backpack. When a 72-year-old male passenger tried to intervene, Hattori allegedly stabbed the man and proceeded to pursue fleeing passengers, splashing them with lighter fluid, which he then ignited. The stabbing victim was hospitalized in a critical condition and 16 other passengers suffered burns and smoke inhalation.

Videos captured on smartphones showed desperate passengers struggling to squeeze out the train's partially opened windows onto the platform of Kokuryo Station.