It's sad that the son killed his father just because of money.

I'm sure the father has all the trust for the son, but his son knowing the father has the bitcoin stored on his phone was probably tempted to steal it. Nowadays, it's hard to trust anyone even your family, so it's better to keep silent about your holding and make sure you don't store in an online wallet if we are speaking of a huge amount of money already.

What disturbed me more here is the Son willing to kill the father just for the money, not the bitcoin stolen by the son.