There was another silence.
“That’s so, isn’t it?” Ewing turned to Glowacki. “That such a person would not be able to tell the difference between the colors?”
“Oh, absolutely,” the doctor responded. “That was another thing the Father and I discussed this morning. We call the impairment a red-green deficiency.”
“It’s cute, Padre,” said Harris, “but I’m afraid you’ve come up with a hypothesis without a foundation. We know that Hunsinger was colorblind. Someone else who knew it would know that he or she didn’t have to be concerned about the color of the liquid containing the poison. There’s no reason to think that it could have been the other way ’round-that the perpetrator couldn’t tell the difference between the bottles.”
“Well, I beg to differ with you, Lieutenant. But I think it does make better sense my way.” Although the priest spoke firmly, he genuinely dreaded this argument. He wished that all of them, especially Lieutenant Harris, whose mild animosity toward himself Koesler had perceived, had bought his theory.
“Let me suggest this, please,” he continued. “Suppose the killer were normal-sighted. Just to avoid fooling with pronouns let me assume the killer was a man.
“He goes to Hunsinger’s apartment. His objective is to get the strychnine into the DMSO. He wants the DMSO to carry the poison into Hunsinger’s bloodstream, quickly killing him. In order to get Hunsinger to use the tainted DMSO, the killer decides to mask the DMSO as shampoo because he knows that the Hun routinely showers at his apartment after the game.
“Now I’ll grant you that the quickest and easiest way of doing this, since the containers of the shampoo and the DMSO are identical-I remember that correctly, don’t I?”
Koznicki nodded slowly, encouragingly.
“Since the containers are identical, the killer simply exchanges the two bottles, relying on Hunsinger’s compulsive routines to cause him to use the DMSO because it’s in the spot reserved for the shampoo. Hunsinger uses the poisonous DMSO because he can’t tell any difference in the bottle shapes, he can’t read the label because of poor eyesight, and he can’t tell the difference in the colors because he’s colorblind.”
“That’s about the way it stacks up,” Harris noted.
“All right,” said Koesler, “but the killer has no plans to revisit the scene of the crime after the murder. In fact, he knows he can’t. Because, again routinely, Hunsinger is showering to prepare for a. . uh. . date.
“So the killer knows that he will necessarily leave behind a scene that looks like this: There will be an open bottle of DMSO on the spot reserved for shampoo. And the police will quickly discover what is in the bottle and the cause of death. In effect, the killer is leaving a clue telling the police that he knows about Hunsinger’s colorblindness-a condition that Hunsinger has gone out of his way to conceal.
“On the other hand, in the theory I propose, the scenario is the same, except for the reason for not exchanging bottles. Now the killer is not leaving a clue for the police. Now the killer is leaving a clear bottle instead of one with a pink liquid, for the very simple and reasonable reason that the killer himself cannot tell the difference.”
Another silence.
“Two things wrong with that, Padre,” said Harris, finally.
“One, you’re thinking-or trying to think-like an investigator. Whereas criminals, in real life, rarely think that ingeniously. That’s why we catch so many of them. You’d be surprised how many homicides are committed in the manner they are simply because that was the simplest way of doing it. It is very possible-probable-the killer didn’t even advert to the different colors. . or, if he did, didn’t care.
“And two, your case is built on the supposition that one of our suspects is. . uh. . color-deficient. When there’s no indication that that is so.”
“Well, again, Lieutenant,” said Koesler, “with all due respect, there may be one or another of the suspects with just that disorder.”
Harris looked at him with disbelief. It was so strong the detective did not have to verbalize his doubts.
“It happened when I visited the Galloway home. The first time, when Mrs. Galloway was questioned, I was vaguely aware that something was wrong, but I couldn’t say what. Then, the other night when our Bible discussion group met there, I became a bit more aware of what it was that was troubling me. It was the color scheme.
“Now God knows I am the last person in the world who might make a living at interior design. But the living room of the Galloway home is somewhat outlandish. I don’t know what the rest of the house is like, but in the living room, they have the walls done in a sort of pale apricot and the upholstered sectional couch and chair are a purplish red. . I believe they call it magenta.”
Both Ewing and Harris had to admit to themselves that they had noticed what they considered the atrocious color scheme. Actually, they had been aware of it long before Koesler, but had simply ascribed it to bad taste and dismissed it from their consideration.
“That,” said Koesler, “is the final detail I checked with Dr. Glowacki.”
“Oh, yes. And I assured the good Father that such colors as he described-an apricot and a magenta-would be a classic kind of blunder of a red-green personality. You see, green plays an important part in this-”
“Is there any way of testing for this?” Harris interrupted. “Is there any way to prove if a person is. . uh. . color-deficient?”
“Oh, my, yes,” said Glowacki. “It’s right here in this little pamphlet, the ‘Ishihara Test for Colour Blindness.’”
“May I?” Harris extended his hand and the doctor gave him the pamphlet. Harris began to page through it.
“You see,” Glowacki explained, “there are ten pages of numbers in that little book. The numbers are formed by outlines of small colored circles.”
“What’s the point?” Harris had completed his scanning of the pamphlet.
“The point,” the doctor responded, “is that normal-sighted people see one thing in that booklet, while color-deficient people see quite another.”
“Could you demonstrate?” Koznicki asked.
“Of course. Sergeant Ewing, would you care to take the test?”
“Sure.”
“Very good.” Glowacki opened the booklet to the first page. “Do you see a number there, Sergeant?”
“Yes. Twelve.”
“That’s correct. Actually, if someone were to miss the twelve, one would be tempted to search for a white cane.” The doctor perceived his attempt at humor was not completely appreciated. His visitors were all business.
“All right,” he turned a page, “and this one, Sergeant?”
“Eight.”
“That’s correct. Now we get into the red-green color deficiency. The color-deficient person sees a three here. And this?”
“A five.”
“The deficient person sees a two.” The doctor continued turning pages.
“Twenty-nine.”
“The deficient person sees seventy.”
“Seventy-four.”
“The deficient sees twenty-one.”
“Seven.”
“The deficient sees nothing here but colored dots.”
“Forty-five.”
“Again, the deficient sees nothing.”
“Two.”
“The deficient sees nothing.” He turned another page.
“There isn’t any number there.” Ewing was surprised; he thought he might have erred.
“No, Sergeant, that’s no mistake.” Glowacki sensed Ewing’s misgiving. “The color-deficient person sees a two here.”
“Sixteen.”
“Again, the deficient person sees no number here.”
“Amazing,” Koznicki commented. “And you say a person with this color deficiency actually sees these numbers that differently from the normal-sighted?”
“Quite. Yes.”
“Now, you see,” said Koesler, “if my theory is correct, someone in the Galloway household has this color deficiency. Either Jay Galloway or his wife, Marjorie. “
“A layman can administer that test, is that correct, Doctor?” Koznicki asked.