Personal jurisdiction only need apply--how would your service decide this issue?

A Soldier is on trial at a general court-martial convened by Commander, 4th Infantry Division & Fort Carson, in Colorado for an off-base killing.  Briefly, the media reports that the charges and prosecution allege that he met his girlfriend/lover at an off-base hotel, and with premeditation killed her.  She too was a Soldier, stationed at Fort Riley in Kansas. After the killing, which he admits, he fled to Ohio, where he was later arrested.

You will recollect that prior to the 1987 case of Solorio v. United States, the military was limited to prosecuting cases where there was subject matter jurisdiction,  The limitation was adopted by the United States Supreme Court in O'Callahan v. Parker, 395 U.S. 258 (1969).

That meant defense counsel filing the occasional motion to dismiss for lack of subject matter jurisdiction.  As part of that motion you had to discuss the Relford factors.  The Mayo case is interesting because on the facts from the media, the military judge's subject matter ruling could go either way were the charges subject to O'Callahan.  Relford factors were a non-exclusive list of reasons for military jurisdiction.  See Relford v. Commandant, 401 U.S. 355 (1971).  The various decisions have undergone quite a bit of discussion and dissection over the years.  But an illuminatus of military law gives a quite reasoned justification for retaining Solorio for the jurisdictional guide, albeit in 1969, he was prescient.   Robinson O. Everett, O’Callahan v. Parker--Milestone or Millstone in Military Justice?, 18 Duke L. J. 853-96 (1969).

When I first read of this I thought there was a quite practical reason why the military has this case -- cost and ease of getting Mayo back to Colorado.  By his leaving and going to Ohio the military was quite entitled to declare him a deserter, issue a DD553 federal arrest warrant, and have him brought back within a few days by Army CID agents -- all on the federal dime and very quickly.  Now the federal (military) dime is being used to fund the prosecution.  That's a somewhat cynical view, but it is often stated by civilian prosecutors as a reason to cede prosecution of military personnel.  That view is tempered by Mayo's waiver of extradition.  Extradition proceedings by the state of Colorado would have taken time, money, and effort.  And it is reported that:

Civilian prosecutors said they turned the case over to the Army at the Army's request. Fort Carson officials said the post has jurisdiction over alleged misconduct by its soldiers, and that military prosecution was appropriate because the victim was also a soldier.

I think the prosecution could still overcome a Relford analysis -- the victim is a Soldier (a blue on blue killing), there appear to have been events and preparations for the crime on base prior to the actual killing, perhaps the threat to report him for misconduct would be a positive jurisdictional factor, and perhaps other evidence not yet put in the media.  The media reports:

Defense attorneys say the episode was caused by love -- claiming a breakup with Walker caused Mayo to unintentionally kill her in grief-driven rage."It was a crime of passion," defense attorney Capt. Michael Gold told a military jury of five officers.* Prosecutors say Mayo killed Walker after she threatened to tell superiors about his lovesick antics'

*Yes, this accused is to be tried by five officers of whom at least four must vote to find him guilty and where the potential punishment is life imprisonment.  We can talk about the impact of small group dynamics on decision making and why the lowest the Supreme Court will allow a civilian jury to go is six, with unanimity -- at another time.  But see Williams v. Florida, 399 U.S. 78 (1970), in the meantime.