I recognize Isadore "Kid Cann" Blumenfeld and the one and only Alvin Karpis, dean of the Alcatraz School of Hard Knocks. Don't know the Boston guy.
The photo you posted earlier of James (King of the Bombers) Belcastro appeared in John Kobler's outstanding biography, "Capone," and is identified as such.


Ntra la porta tua lu sangu � sparsu,
E nun me mporta si ce muoru accisu...
E s'iddu muoru e vaju mparadisu
Si nun ce truovo a ttia, mancu ce trasu.