Everyone waited breathlessly for Kennedy’s next move.  Suddenly Kennedy flushed.  I could see that he became genuinely angry.

“In this room,” he exclaimed, “there sits the most unscrupulous, cold-blooded, inhuman being I have ever known.  Yet he maintains silence, believing still that he can defy the scientific evidence of his crimes.  I have not yet mentioned, however, the real proof of his guilt.”

Kennedy picked up one of the little envelopes, one which contained a blood smear.  “During the explosion this morning a number of you were cut by falling glass.  You will remember that I bound up your cuts, carefully cleansing each one and wiping away the blood.  That gave me a sample of the blood of everyone but Miss Loring and Mr. Shirley.  Subsequently, without their knowledge, I obtained a sample from each of them.  Thus I have a specimen from everyone concerned, or possibly concerned in the murders.”

He glanced about, but even now there was no telltale revelation.

“I have analyzed these and one shows that the person from whom I obtained the sample has been inoculated with antivenin.  The mark on the envelope is the same as the mark on the envelope containing the towel fibers, a double proof.  Furthermore, I am prepared to show that it is the same blood as the blood upon the portiere.”  He faced me.  All at once his voice carried the sharpness of a whip.  “Walter, relieve Mackay at the door and take his weapon.  Let no one out.  Mackay, come here!”

An instant later the district attorney leaned over.  He glanced at the mark indicated by Kennedy, then whispered a name.  The next instant Kennedy rose.  “I thought so,” he muttered.

Raising his voice, he addressed all of us.

“Here is a man who thought crime so long that he believed he could get away with—­murder!  Not only did he commit a second murder and plan a third to cover the first, but he planted evidence against nearly all of you.  He dropped the ampulla in McGroarty’s car to implicate any one of four people.  He coolly stole a cigarette case to put it where it would be found after the film fire and clinch suspicion.

“For all this, what justification has he had?  Jealousy, jealousy of the narrowest, most primitive, sort actuated him.  Not only was he willing to kill Stella Lamar, but he sought to destroy every foot of negative in which she had appeared.  He was jealous of her success, greater than his, jealous of her interest in other men, greater than her interest in him.  Her divorce was maneuvered directly by him simply because he thought it would hurt and humiliate her, and for no other reason.

“When nothing seemed to stop her, on her upward climb, when he realized that she was as ambitious as he was and that her position in the picture world alone interested her, he sought by devious means, by subtle schemes, by spreading dissatisfaction and encouraging dissension, to wreck the company which had made her.  At the end—­he killed her—­waiting craftily until she was at the very climax of her finest piece of work, the opening scenes of ‘The Black Terror.’”