Wait, so you're changing your theory/profile? Reading thread #1, your earlier theory was that these were not related in no way shape or form. So much for profiling these days. In my opinion, it does no good to anyone to list reasons of why something could have been done "drugs, mental illness, trauma, life circumstance", solar flares, global warming, etc..
Since we don't have all the details, to me its even more important to stick to the profile because there are fundamental reasons why killers do certain things, like pick a two victims that in some pics, look almost identical or the process of escalation and many other things they had in common. Looking back at thread #1, some people thought they were connected and were listing similarities which I recall you casting lots of doubt. I believe nobody know's if they are connected or not, but I will not shape-shift just to sound wise.