Now," he continued, after the first storm of remorse had spent itself and we were all outwardly composed again, "we have said nothing whatever of the most mysterious feature of the case, the firing of the shot.The murderer could have thrust the weapon into the pocket or the folds of this coat"--here he drew forth the automobile coat and held it aloft, displaying the bullet hole" and he or she (I will not say which) could have discharged the pistol unseen.By removing and secreting the weapon afterward one very important piece of evidence would be suppressed.This person could have used such a cartridge as I have here, made with smokeless powder, and the coat would have concealed the flash of the shot very effectively.There would have been no smoke.But neither this coat nor even a heavy blanket would have deadened the report of the shot.
"What are we to think of that? Only one thing.I have often wondered why the thing wasn't done before.In fact I have been waiting for it to occur.There is an invention that makes it almost possible to strike a man down with impunity in broad daylight in any place where there is sufficient noise to cover up a click, a slight 'Pouf!' and the whir of the bullet in the air.
"I refer to this little device of a Hartford inventor.I place it over the muzzle of the thirty-two-calibre revolver I have so far been using--so.Now, Mr.Jameson, if you will sit at that typewriter over there and write--anything so long as you keep the keys clicking.The inspector will start that imitation stock-ticker in the corner.Now we are ready.I cover the pistol with a cloth.I defy anyone in this room to tell me the exact moment when I discharged the pistol.I could have shot any of you, and an outsider not in the secret would never have thought that I was the culprit.To a certain extent I have reproduced the conditions under which this shooting occurred.
"At once on being sure of this feature of the case I despatched a man to Hartford to see this inventor.The man obtained from him a complete list of all the dealers in New York to whom such devices had been sold.The man also traced every sale of those dealers.
He did not actually obtain the weapon, but if he is working on schedule-time according to agreement he is at this moment armed with a search-warrant and is ransacking every possible place where the person suspected of this crime could have concealed his weapon.For, one of the persons intimately connected with this case purchased not long ago a silencer for a thirty-two-calibre revolver, and I presume that that person carried the gun and the silencer at the time of the murder of Kerr Parker."Kennedy concluded in triumph, his voice high pitched, his eyes flashing.Yet to all outward appearance not a heart-beat was quickened.Someone in that room had an amazing store of self-possession.The fear flitted across my mind that even at the last Kennedy was baffled.
"I had anticipated some such anti-climax," he continued after a moment."I am prepared for it."He touched a bell, and the door to the next room opened.One of Kennedy's graduate students stepped in.
"You have the records, Whiting" he asked.
"Yes, Professor."
"I may say," said Kennedy, "that each of your chairs is wired under the arm in such a way as to betray on an appropriate indicator in the next room every sudden and undue emotion.Though it may be concealed from the eye, even of one like me who stands facing you, such emotion is nevertheless expressed by physical pressure on the arms of the chair.It is a test that is used frequently with students to demonstrate various points of psychology.You needn't raise your arms from the chairs, ladies and gentlemen.The tests are all over now.What did they show, Whiting?"The student read what he had been noting in the next room.At the production of the coat during the demonstration of the markings of the bullet, Mrs.Parker had betrayed great emotion, Mr.Bruce had done likewise, and nothing more than ordinary emotion had been noted for the rest of us.Miss La Neige's automatic record during the tracing out of the sending of the note to Parker had been especially unfavourable to her; Mr.Bruce showed almost as much excitement; Mrs.Parker very little and Downey very little.
It was all set forth in curves drawn by self-recording pens on regular ruled paper.The student had merely noted what took place in the, lecture-room as corresponding to these curves.
"At the mention of the noiseless gun," said Kennedy, bending over the record, while the student pointed it out to him and we leaned forward to catch his words, "I find that the curves of Miss La Neige, Mrs.Parker, and Mr.Downey are only so far from normal as would be natural.All of them were witnessing a thing for the first time with only curiosity and no fear.The curve made by Mr.
Bruce shows great agitation and--"
I heard a metallic click at my side and turned hastily.It was Inspector Barney O'Connor, who had stepped out of the shadow with a pair of hand-cuffs.
"James Bruce, you are under arrest," he said.
There flashed on my mind, and I think on the minds of some of the others, a picture of another electrically wired chair.
