An analysis of the sediment in the husband's coffee cup establishes the presence of arsenic. It must be inferred that the wife's cup contained none of the poison, for she developed no symptoms of poisoning after the meal.
The servants declare that the wife invariably made the after-dinner coffee in a percolator that stood on the sideboard. On the night in question, she had boiled the coffee, but none of the servants had seen her draw it from the percolator or serve it in the cups. But all of them assert that for a year or more it had been the wife's custom to do the serving, so it is a fair inference that the husband did not leave his seat at the table to help himself to coffee, on the occasion of his fatal illness. No one but the wife being in the room with him, and it having been ascertained that she purchased the arsenic, hers was the exclusive opportunity to drop it into the cup—and the evidence against her is complete.
A case of this nature is not established by the deductive methods of a Lecocq, but by the patient labor of a score or a half score of detectives intelligently guided by their chief. The druggist who sold the poison was found after a canvas of perhaps three or four hundred apothecaries. The domestic strife in the victim's home was disclosed to the police by relatives of the husband, whose interests naturally conflicted with those of the wife. Other evidence was furnished reluctantly by the servants, and, through the collective efforts of all the detectives, the woman's crime has been reconstructed in a way calculated to convince the ordinary juror.
It was because Detective-Lieutenant Britz was endowed with a rare combination of talents that enabled him to direct the work of others, even while participating actively in the physical search for evidence, that he ranked as the foremost detective of the Central Office. Had he been merely a shrewd, capable, resourceful investigator, he could never have attained to his present eminence.
Britz occupied a position subordinate to Manning, but his reputation far exceeded that of the latter. And Manning, conscious of the value of his lieutenant, reserved his services for the more baffling mysteries which the Central Office from time to time was called upon to solve.
He was not jealous of Britz's reputation, for he was aware that the lieutenant did not aspire to the head of the bureau, would not have accepted the promotion had it been offered. As a subordinate Britz was relieved of all the routine which occupied so much of the chief's time, so that he could devote all his energies to the single case to which he was assigned.
Moreover, Manning by purely voluntary renunciation, exercised none of the supervision over Britz which his higher rank authorized. So that Britz having been given command of the Whitmore case, was at liberty to proceed with the investigation along his own lines.
On the morning following the escape of the butler with the documents which the detective had gathered in Beard's home, Britz was at his desk in Police Headquarters at eight o'clock. He had not troubled to search for the vanished servant, arguing that the man would be easily traced through his loyalty to Beard.
The first thing Britz did was to call up Dr. Henderson, the Coroner's physician.
"I am sending the police photographer to the autopsy on Whitmore," he said. "Please don't cut the body or probe the wound until he has taken a picture of the bullet hole. It is most important. Also, let me have a copy of your report on the autopsy as soon as possible."