Identificaciones de stevecollins

This interesting robber fly was hanging underneath some purslane, eating a little bee that had probably been visiting some blooming catnip in the area. (It had also visited a milkweed -- you can see a pollinium attached to one leg.)
The robber fly got disturbed and moved a bit, but rehung itself by one leg to start eating again, so it looks like this odd position is a choice rather than chance.
The fly was mid-sized as robber flies go -- in the 1.5-2.0 cm range. It was rusty colored. I'm not sure that I've seen one like this before.