You don't speculate when a person has died and you need to find the SOB that did it. You find the path, and you follow it. The answer appears at the end.
The only other way that works is in books (Murder Mysteries) and TV (CSI, and others). Where an author sets it up, and works it backwards.
Fiction isn't reality.
Come live with me for a few weeks, and we'll experience some reality. You'll see how blood stains actually work, when you help deal with feral hogs.
Phah! You are a yankee wannabe. Wouldn't last a few days in the woods down here.
And don't have a clue how to follow a game trail. The big hint is that you don't start with where you think they are.
/johnny
See, that's the thing. When Tiffany made her 911 call, I can't recall she was desperate to have someone come and try to HELP her injured husband. I mean, she wasn't really sure he was dead.
She seemed to be reporting the incident, rather than desperately seeking immediate assistance.
I would have been begging the authorities to immediately go after him...EVEN IF he was on the Mexican side.
She should have give them the option of saying "no"..