I think that is a disgraceful article.
It's all based on 'sources'.
So some anonymous person has told a reporter about an acrimonious break up, and then someone has dug into that, and been stonewalled. But they printed it anyway even though there is no reason whatsoever to link it to the murders at this stage.
(And even if at some later point, after psych reports, it is found it was somehow a formative event, it still not remotely the fault of any person whose path crossed his in the past. It's solely him. Nothing, apart from specific danger, ever justifies homicide).