Ironically the only thing about these 2 that make me think they might actually be factually guilty is that they don't look the part.
Seems if the Thai Police were going to pin this on any convenient Burmese workers to save their precious tourism, they would have chosen a pair that looked bigger, darker, meaner and stronger.
Going to Google News and running "Thailand murders" it appears the majority of the British press is not being as critical of these arrests as one might hope.