In the article, it mentions that Bobby Doyle was one of the hitmen that took out Maranzano in his offices.

So we have many different versions of who killed Maranzano.

1. 4 Jews trained by Meyer Lanksy.

2. Red Levine, Vito Genovese, Joe Adonis, and Albert Anastasia did it.

3. Bobby Doyle and some others did it.

"For us, rubbin'out a Mustache was just like makin' way for a new building, like we was in the construction business."