Why was Saddam Hussein put in prison?

Saddam Hussein was put into prison and Hanged for Genocide, War Crimes and Crimes Against Humanity.

Saddam was wanted for the 1988 attack of Halabja with Mustard Gas and Nerve Agents that killed over 5,000 people and that mamed, disfigured, and seriously debilitated over 10,000 more. The Killing of Religious Figures in 1974. Killing of the Kurds in 1983. Killing members of Political Parties. Displacing Kurds in the mid 80's. Suppressing Kurdish and Shiite uprisings in 1991 and the invasion of Kuwait in 1991.

to make a long story short . . . . . he was a bad person.