Obviously, we all need to await the full facts of this case, assuming they are eventully revealed. Some questionable points though:
It is alleged the intruder carried 290000 bahts on him. Quite bulky and for what purpose?
His sister claims she knew he had the money on him, even though she lives nowhere near.
Wife claims to have slept through it all.
If he was invited by the wife, why did she do so when the husband might have been at home?
If invited, why did he not use the door and why carry a gun unless his intention was to kill the husband?
Could the husband have been aware of the plot and decided to kill the intruder when he arrived?
Perhaps the gun was thrown into a nearby pond by the husband, once he had disarmed the intruder to ensure that it could not be repossessed by the intruder and used against the husband.
The intruder was tied up presumably because he was still alive and to avoid any further attack?
The police were called, possibly after a delay, due to shock and doubt as to how to proceed.
And so it goes on. Hopefully, the police will do a thorough job and get tothe botom of it all.