I had a look for identification, but the problem is that most printed versions of the photo cut off everyone to the right of Capone so they don't identify them. If there's a newspaper that published the full photo then they may have the names, but I've been unable to identify an early source that did so. Getty Images has three different listings for the source of the photo with different dates attached to them. It might be worth reaching out to Getty to see if you can get any further information and if the press organization which originally held it had all of the persons identified. That would be my only guess on how to be sure.

You may be interested in looking at some of the other photos of the case aftermath to see if you can identify him there as well.