I've always believed that the Columbo shooting was an inside job. Columbo formed the League as a way to pressure law enforcement to drop charges against his son and him. All his troops were expected to spend time recruiting individuals and businesses to join the League--with Columbo keeping all the money. Columbo's high public profile was anathema to the Commission, and his denial that the Mafia existed weakened his members' ability to extort victims due to the fear factor.

As for the shooting: How did Jerome Johnson, a no-account who spent his time hanging around college campuses trying to seduce college girls, get an expensive Bolex movie camera and press credentials, if not from family members? Who but Columbo's bodyguards would let him and the girl he was with get close to Columbo? Who but they would kill him instantly while letting his girlfriend disappear from the podium? And, I wouldn't be surprised if NYPD had a hand in it--notice how no one was arrested in Johnson's killing?

Of course Columbo had to go. And, who would pick up the pieces if not The Snake, who headed the most powerful faction in the family.