You ask me -- he had tried to knock over a liquour store and was on the lam.
Yeah, it is kind of pointless to speculate on the motive of the murder, if there was a murder.
They left the axe "to make it look like an accident". And when was the coroner suppose to show up?? And the trial judge?
Fun stuff though!!!
It appears that Otzi was the victim of a hate crime: http://www.straightdope.com/classics/a3_229.html