Several years back I read a book titled (IIRC), Making of a Mossad Agent, which told the processes of becoming and working as an Israeli Intelligence operative. It briefly mentioned the Mossad doing their own investigation into the JFK assassination for the purpose of finding out the truth as to what went down, who was REALLY behind it, their interest being whether it could cause Israel problems. Per the book, they found out what they wanted to know and satisfied that it wouldn't effect Israel in any way, they just let it go and went on about tending to their own affairs.