Military bases are federal land, Perry has no jurisdiction.
You are mistaken.
Military bases are federally owned property, but they are state land. The discernment between state and federal land must go back to the original deeds and declaration of the property. In the case of Ft Hood, the land was part of the state of Texas prior to becoming a state of the United States of America. The land still falls under the jurisdiction of the State.
The base might have MOA/MOUs with local law enforcement wherein the county Sheriff or the city police allow the Commanding General of the post to handle law enforcement within the base limits by use of UCMJ and to maintain good order, but technically, if a felony occurs, the local police/Sheriff have the jurisdiction to take control of the crime scene.
I suspect the same situation exists regarding the San Antonio hospital where the criminal is now located by reports.
If memory serves me correctly, the only federal land in the USMC is the brig at Quantico, which is part of the reason Hinckly was imprisoned there. There are more Army bases with federal land, but one has to go back to how the land was originally broght into federal control. If previously a State, then it technically is State land, even though owned at present by the Federal government.
What about for civilian murder charges?
10th Amendment. Time to take the country back. The Feds have been infiltrated by Islamic sleepers and not so sleepere. Time to wake up.