Complex sentence: The intruder could have been a pedophile and/or sexual sadist or the murder may have occurred as an act of revenge or retaliation against one of the Ramsey family members, most likely John Ramsey.
Split into simpler sentences: The intruder could have been a pedophile and/or sexual sadist. Alternatively, the murder may have occurred as an act of revenge or retaliation against one of the Ramsey family members, most likely John Ramsey.