The man on the right is Dominick Maltese, Mary’s great uncle. The man on the left is unidentified, but most likely a colleague. Dominick was a police officer and an FBI agent, and did a lot of undercover work.
Hope you enjoy these great old photos! At that page, you can even subscribe to the photos in this set with an RSS reader, if you like.
Also: This photo is the back of the above photo, which was actually a post card.
Another also: You can view all of the heritage photos in a slideshow here.