After Hennessey killed Thomas Devereaux and got off, he was not lynched. He may have been killed by friends of Devereaux. The stories of the Mafia doing the murder grew over the past 20 years with the publication of a book about it, that was slanted against the men lynched. If the Sicilians had done it, they would never have ben found not guilty in that city in that time period. After the lynching President Roosevelt congratulated the lynch mob.
One of the theories was that Domonik O'Malley was involved in killing Hennessey. O'Malley was good friends with Devereaux. Anything is possible but I doubt it.
