Dr. Watson

Oh, that should be obvious.

He wanted to ensure that his sister's fiancée would enjoy undisputed title to the name of the States.

How did you know it was Nolan?

When I examined the authentic suit of armor.

You see, it was obvious it had never been worn.

But I still don't quite understand... Oh, come now, old chap.

The suit of armor was in a heap on the floor.

Yeah?

And if it had been hastily discarded and get... Well, the gauntlets were on top of the pile, remember?

That's right, they were.

If the suit had really been worn, the gauntlets would have been the first things to have been taken off, and so would have been underneath the pile.

Obviously, therefore, the armor had been disarranged in order to make people believe the real ghost had walked.

After the American's death, the suspects were four.

Miss Nolan, her brother, Thomas, the butler, and Earl himself.

Well, I ruled out Mrs. McClintock because, remember, she was standing behind us at the time of the murder.

I'm beginning to understand.

All the suspects except Nolan were small enough to have worn the armor.

That's right.

Therefore, only he could have pretended to use it.

Pretended?