M-F they accept walk ins after 1pm. Admission is free.
Law enforcement and military can receive free tickets. They may register online or get free tickets/admission by simply showing up.
free after 1pm
Depending on when you plan to go I suggest you get a pass in advance. They are available through the website. We only had 3 hours to visit and that is no where near enough time to do justice to the exhibit.
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