It is held by Gemini closely as it contains the winnings she and her husband obtained during their stay in Las Vegas. She will not let go of the case, rejecting any item or weapon that Chuck offers her. The only way Chuck can obtain it is by killing her.
It is also held by Janus Razo and Woodrow Rutherford, and if they are killed, the cases can be taken and broken for $50,000 each. Rescuing Janus will reward you with $70,000 while rescuing Woodrow gives you $50,000 .
In Dead Rising 2, although Gemini holds $30,000 in the case, breaking the case open will only give Chuck $800.
Contrary to popular belief, in Dead Rising 2: Off the Record, picking up a Money Case, then leaving and re-entering the area will make the Money Case respawn. This does not, however, apply to all cases in Sandbox Mode if you are still carrying it.
In the OTR guide, this is listed as a Mission Only weapon, which is incorrect.