The FBI had no reason to kill Colombo. The IACRL was actually a good thing for the FBI. No a majority were not with the families, but it allowed the FBI to take notice of members who joined to be looked into and be put on the radar. The Colombo family had many members, followed by the Gambinos, and Lucchese. The Bonannos and Genovese also had a few of their members identified from it. The extortion was ludacris and allowed the FBI to take a closer look. What I mean is, is that families would tell Italian store and shopkeepers to put the sticker on their window and pay a fee or else. No, not all the stores were extorted or theated as most shopkeepers had no problem as they felt the organization was making a difference.

I already gave my answer on who I believe was responsible and there is a trail. Lots of trails actually. One thing is this, the Commission did not give the Ok, and did their investigation, which pointed to within the Colombo family. They automatically suspected the Gallos, although Joe was already their number two suspect, the number one suspect is probably lost to history.