Even outside of Baltimore, no judge is going to grant a motion to dismiss this case. Some of the charges against some of the defendants may end up dismissed, but not the whole case. In light of the allegations that the officers violated department policy by placing Gray in the van in handcuffs and ankle restraints but no seatbelt, repeatedly refused Gray's requests for medical attention,* and Gray wound up dead, no judge is going to dismiss this case before it gets to a jury.
* There are some radio communications that indicate that the officers eventually did request an ambulance, but not until the van's final stop, an hour after Gray was taken into custody.
Are you sure about it?
Since the dispatch tapes of Gray’s transport have been out for a good while, you would have to search for them now on The Conservative Treehouse website. Those tapes show that medical assistance was requested for Gray at the arrest location and several communications were made between the officers, dispatch, and the EMT’s during transport. The officers even left an officer behind to redirect the EMT’s as they tried to coordinate with them.