ft his visiting card!"

All eyes were turned in his direction.

He continued:

"Cracksmen, criminals of all kinds have their idiosyncrasies,
their peculiarities. They do certain things and thus leave a broad
trail for the police to follow. The police know these peculiarities,
they have a record of them. Here is a bird who does an unusual thing,
he eats an enormous quantity of food. He is an expert; he has probably
done it before. The police are sure to get him. During my tenure of
office as Police Commissioner of New York, I have seen it work out this
way lots of times. They never learn, the criminals don't; they never
learn."

McCall nodded. "You're right, Commissioner. Professor Brierly
suggested that yesterday, when he was discussing the murder of
Morris Miller. The murderer in that case left even more pronounced
clues than this one you are now discussing. Professor Brierly then
said that the police must surely have a record of a man who does
things in such a way."

"Sure to have," responded McGuire. He arose and stretched his
short huge bulk. "This is something like it. We now have something
tangible, something definite. It was the damnable inaction that
was beginning to get on my nerves. I'm going to use your phone,
Judge."

They heard his voice rumbling at the telephone in the adjoining
room. They were still conscious of his deep growling voice when
Professor Brierly, Jimmy and McCall departed.

The two younger men succeeded in warding off from Professor
Brierly the barrage of questions that was fired at him by the
horde of men and women who still waited about, hoping for a crumb
of information in addition to that which had been furnished.

When they were free of the crowd of newspaper men, Jimmy asked:

"Did the police tell you, Professor, what the additional bit of
evidence was?"

"Yes, when I convinced them it was not suicide they made a more
extended search of the apartment. It was then they learned that an
expert cracksman had entered, that an expert had opened the safe
without blowing it open or forcing it open. This cracksman,
however, did things in a way that only about half a dozen men in
the country do it and the police have all of them tagged.

"The additional individual evidence was entirely accidental. They
found under the safe a small nail file. On its smooth portion they
found a clear thumb and forefinger print. They were rather
mysterious about it, so evidently they think they can l