As a woman who runs alone early in the morning often when it's dark, it's nice to see LetsRun's response is different from articles on MSM, which generally say women (and people in general) shouldn't run alone early in the morning. It seems Letsrunners realize it's either run alone or run on the treadmill, practically speaking, for many adults with kids and responsibilities.
I don't know anything about Memphis, but I obviously hope the best for this woman. She was a Boston qualifier, and I bet she ran a lot. I'm training for a marathon in the early morning (though not that early morning) in a suburb of Seattle, so it was definitely creepy to read about this. With that said, statistically speaking, your chance of being murdered while running regardless of your gender and race and when you run, is incredibly low.
I do think your chance of being assaulted is much, much higher, but probably still pretty low if you run in a safe area.