This story is getting only muted national coverage here in the US, probably because of the races involved (victim-white woman, suspect-black male). The UK Daily Mail has covered it well since day 1.
Judging by the way it was played out, him staying back and biding time until the drug made her easy to manage, I fear he has done this before.
A shopkeeper saw her stumbling and offered to help her but this suspect came up and took control of the situation, putting his arm around her, making the shopkeeper think they were a pair and the girl was just tipsy.
If there were others involved, she might still be alive. I hope so...