Bill,

The beheadings in Syria of three victims gained massive, global publicity and no doubt the worst imagery will remain online for a long time.

As a Pakistani writer remindes us beheadings are not new:
While IS sparked global outrage following the release of the recorded beheading of Foley, last year the TTP had released an even gorier video of militants playing football with decapitated heads of Pakistani police officers.
I will post her commentary elsewhere in a moment as it relates to another topic:http://strifeblog.org/2014/09/26/the...the-caliphate/

How many other murder victims in the USA have been beheaded, say in the last year?

About a month ago a mentally deranged man beheaded an old lady in north London. No-one has commented since on his motive. First link is to her funeral:http://www.bbc.co.uk/news/uk-england-london-29343759 and an earlier report:http://www.bbc.co.uk/news/uk-england-29068391

Leaving media hype aside I think it best to wait today before deciding what the man's motivation.