Jim,
"The investigations have hardly started when you are suggesting that the police call off the hounds"

I somehow doubt that my posts will influence them much.
I am confident that they will explore the possibility of accomplices.
It really has been widely reported that he is believed to have acted alone.

His contact with far Right groups, as I keep saying, is what you would expect.
Even if he did act alone, others could be convicted of incitement, as happened with the female Jihadist I referred to.