I find the story has a couple hitches.... Why is both Aikau and his son beaten? And why is there a sharp object that was poked in his son.

Could it'd be that both he and his son were beaten to get information and Aikau finally gave in when his son was poked with something sharp?

Hope that a good autopsy on both would shed more light on the manner of their deaths. And there really should be an investigation. For example does he have any history of mental illness. We might suspect that after rehabilitation, his mental illness started taking over and lead him into this.

We need to have more facts please before we can assume that this is murder-suicide.