The man in the photograph is the man's own son.
The head surgeon is the Alfred's mother.
EGG'S YOLK OR EGG YOLK?
Neither. Egg yolks are yellow, not white.
If Richard is innocent and Tommy is innocent, David must be guilty. If Richard is guilty and Tommy is innocent, Richard's only possible accomplice is David. David must therefore be guilty in either case.
A PROBLEM OF TIME
Obviously, when they meet, they will both be the same distance from London.
HANGED OR DROWNED
All he need say is "I'll be hanged"