According to the below link, it appears that that the Royal Thai Police are running out of leads as to those culpable in the double-homicide of British citizens David Miller, 24, and Hannah Witheridge, 23:
Thailand's police chief-designate Pol. Gen. Somyos Pumpanmuang has arrived in Koh Tao to investigate the murders of British backpackers David Miller and Hannah Witheridge after DNA results ruled out brothers Christopher and James Ware.
The young bodies of the young British couple were found by beach cleaners on Monday (September 15).
COMMENT: Faced with diminishing leads in the investigation, which has captivated the world media, my suggestion is that Thai authorities ask for forensic assistance of their British counterparts.
After ruling out all twelve suspects, police have admitted they "really don't know where to look now." Major general Kiattipong Khawsamang conceded it was "difficult to say" if the killer was still on the island or not."
Pol. Gen. Somyos Pumpanmuang will brief journalists later today (September 18) on the search for the assailant(s) of David Miller and Hannah Witheridge.
Police yesterday (September 17) ruled out twelve suspects in the double-homicide, including British brothers Christopher and James Ware.
Christopher, 25, was prevented from Suvarnabhumi Airport on Tuesday (September 16) and questioned, after police found what they believed was a pair of his bloodstained trousers in the luggage of Miller.
Christopher Ware had been staying in the same room as Miller, but police now say there is no evidence against either brother.