“A damp state following a rainstorm, followed in turn by sufficient fair weather to permit the impression to dry out.”
“Was such a state in existence?”
“In one case—yes. There was a storm between one and three on the afternoon of the nineteenth. We’ll call the tire impressions A, B 1 and 2, and C. A showed only very vague traces of a very broad, massive tire on a heavy car. It was almost obliterated, showing that it must have been there either before or during the downpour.”
“Would those tracks have corresponded to the ones on Mr. Farwell’s car?”
“There were absolutely no distinguishing tire marks left; it could have been Mr. Farwell’s or any other large car. C had come much later, when the ground had had time to dry out considerably. They were the traces of a medium-sized tire on fairly dry ground. They cut across the tracks left by both A and B.”
“Could they have been made by Mr. Conroy’s car?”
“I think that very likely they were. I checked up as well as possible under the conditions, and they corresponded all right.”
“What about the B impressions?”
“Both the B impressions were as sharp and distinct as though they had been made in wax. They were made by the same car; judging from the soil conditions, at an interval of an hour or so. We made a series of tests later to see how long it retained moisture.”
“Of what nature were these impressions, sergeant?”