One of the nice things about being a Mafia Don is that you get to make the rules for your family. One of the Don's prerogatives is qualifications for being made, and that may or may not include having killed someone. As Ivy said, probably no man would be made whom the Don didn't think would kill on orders, but that's a practical matter, not written in any "rulebook" (which doesn't exist anyway).

If memory serves, Fat Vinny Teresa, in his book, "My Life in the Mafia," said that Patriarca didn't have a ceremony for made men, complete with the finger-pricking, burning saint's card, kisses on cheeks, etc.--the stuff of legend that most people think is universal in Mafia families. "They just called you to the Office and told you that you were in," he said.