This is just conspiracy theory stuff, using random facts to suit a particular narrative. To look at your “evidence”: There are five empty suitcases in my house right now of varying sizes. We use them when we travel and they sit empty in our house when we are at home. A lot of Thai teenagers are a small size and assuming he picked her for sex at his place, maybe he prefers girls of a small stature. Many men do and they aren’t serial killers. Maybe he continued his normal routine because he was trying to work out what to do and the brain surgery that he had slowed his thinking. I’m surprised that you missed out that he had knives in his cutlery drawer, so he must be a serial killer. I mean, come on. I don’t doubt he killed the girl, my own opinion is that it was an argument, that became a fight, that ended in murder. There is nothing that suggests he targeted his victim with murder in mind and even less than nothing that suggests he is a serial killer.