He could have been using the computer to look at porn, could be as simple as that. He stayed in the room for a few days so that is the most likely reason. Then destroys the hard drive so he doesn’t wind up like his brother who just got caught with kiddie porn.
Trash can be recovered but I highly doubt they dug through the entire trash from Mandalay. Wouldn’t be hard to get rid of a hard drive on a property that large.
The kiddie porn angle...I’ve heard lots of theories regarding the Las Vegas massacre..Might as well throw that in too.