It's a motive they are considering. But the motive isn't completely that he's just an Islamic convert. There, supposedly as little as we are aware, is more info dating back to this man's past.
I asked this question earlier and you appear to have the answer. Could you provide me the link where it is proven a Christian committed this crime in some sort of name of Christianity, perhaps?
Just out of curiosity, and maybe this was already covered in this thread, but your article states nothing about being shot dead by 'right wing', but your thread title says it's so.