I'm sorry that the girl is dead, and I hope that justice is done.
As for other runners' better insuring their safety:
1) A cell phone is not a bad idea, particularly if you're going to be running (especially if alone) in an infrequently-traveled area. If you fall or otherwise get hurt, you might be able to call and get help. It could be a lifesaver.
2) However, about the only help a phone could be in case of an assault would be if you could throw it hard enough (and luckily enough) to disable the attacker. But these men almost always attack from behind (or the blind side) and knock their victim down--not even an opportunity to throw the phone, much less make a call from it. And rarely an opportunity to put up much of a fight.
3) So your best bet is to run in areas that are pretty heavily trafficked and/or always to run with a partner.
4) I do agree that running without headphones is an aid to safety, regardless of the runner's sex or running venue.