So if it is a Muslim committing an atrocity it = Radicalisation by Islam
If it's a white guy it = mental health issues.
Don't you just love the consistency of approach.
Some Muslims are white guys.
You can be radicalised by reading stuff on political Islam or Nazi stuff.
Both can make someone have mental health issues, or can make their problems worse.
Anyway in this instance it depends if the attacker has a history of it and needed treatment for it.
The colour of his skin is irrelevant.
If someone has had treatment in the past it is relevant to look at it.
It appears both the killer of Jo Cox and the attacker in the Orlando gay club attack both had treatment for a mental illness of some sort prior to this.
How relevant it is, needs to be determined.