Joker was a dangerous criminal and as such was imprisoned in a stasis chamber by the World Army at the Arkham Base.
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History
FIRST APPEARANCE: Earth 2 #17 (January, 2014)
APPEARANCE OF DEATH: Earth 2 #18 (February, 2014)
After being imprisoned for an unknown period of time, the Joker was eventually discovered by the new Batman who was freeing some of the prisoners to aid him. The new Batman did not free Joker however, but instead shot him in the head; killing him.
