On cross-examination Rosser was not able to refute much of Scott’s testimony. However, he did establish that at the coroner’s inquest Scott had testified he heard nothing of the conversation between Lee and Frank and then at the murder trial claimed that Frank had declared: “Well, they have got me, too.” Rosser forced Scott to admit that this was a change in his testimony.

As for Frank’s nervousness, Scott had never mentioned it at the inquest. When Rosser asked him about this, Scott said: “At the time, Frank’s nervousness had no effect whatever on my mind, because I did not consider Frank any suspect at all. Knowing the man was under a strain, I did not suspect him at all at that time, and therefore it was not a material fact at the time. I did not consider him a suspect.” This is impossible to believe, for Scott admitted that on the previous day, when he first interviewed the defendant, he “knew then that Frank was under strong suspicion.”

Though Rosser blundered later in the trial, he was powerful and effective when confronting the state’s witness John Black, the city detective who worked with Scott on the case. Through careful and insistent questioning, Rosser all but destroyed Black’s testimony against Frank. At one point Black was so confused that he took six minutes to answer a question, and near the end of his testimony he declared, “I don’t like to admit that I’m crossed up, Colonel Rosser, but you have got me in that kind of a fix and I don’t know where I’m at.” No surprise then that the headlines of the story of Black’s testimony read: DEFENSE RIDDLES JOHN BLACK’S TESTIMONY/SLEUTH CONFUSED UNDER MERCILESS CROSS-QUESTIONS OF LUTHER ROSSER . The Atlanta Georgian said, “There is a feeling growing more fixed every day,…that the state, if it hopes to win, must set up something more than it has yet made public.”

When Scott took the stand, he proved a more difficult target for Rosser’s cross-examination than Black had been. Dorsey was able to get Scott to give testimony that damaged the defense’s case, and as we have seen, because much of this was a surprise to the defense, Rosser was hard-pressed to get Scott to retract it. Summarizing the day’s testimony, the Atlanta Constitution declared, “Harry Scott…proved a strong witness for the state, although at first it looked as if he would prove of more value to the defense.” Though the trial had been under way for several days, Scott was the first witness who really aided the case against Frank.

Rosser was emphatic about how the changes in Scott’s testimony had damaged the defense. In the trial over the unpaid Pinkerton bill, he declared: “At no time prior to the trial of the Frank case, was I informed verbally by Mr. Scott…that he intended to change the testimony that he gave at the Coroner’s inquest and the information that he gave me in his reports as to the matter of Frank’s saying ‘no’ or ‘I don’t know[.]’ He certainly did not tell me before he went on the stand at the trial that he was going to testify that Frank told him that Gantt was intimate with Mary Phagan. His testimony at the trial on that point certainly surprised me. In my opinion, as an attorney, that was certainly a matter of materiality and consequence in the case.”

On cross-examination Rosser expressed in even stronger terms what he considered Scott’s duplicity: “Mr. Scott never made any effort to get a conference with the attorneys for the defense before the trial. I did not know that Mr. Scott had any opinion about the case that had not been communicated to me…and everything he knew was supposed to have been put in writing in the reports, that he had made to me, and I supposed that those reports were true. If I had thought that Mr. Scott was going to testify anything different from what was in the writings that had been submitted to me, I would have wanted to talk to him.”

SCOTT CLAIMED THAT AFTER HE HAD DISCUSSED his testimony with Dorsey, he attempted to speak to Frank’s attorneys but was refused an interview. But surely, if Frank’s lawyers had had any indication that Scott’s testimony at the murder trial would differ from what he’d said at the coroner’s inquest or in his written reports, they would have found time to talk to him.

More plausible is that even though he was employed by the defense lawyers, Scott had been conspiring with Dorsey for some time to establish Frank’s guilt. This is nowhere more evident than in the role he played in the several statements made by the prosecution’s most devastating witness, Jim Conley.

At first Conley had been overlooked as a possible suspect because the investigators believed his claim that he could not write. But at some point two Pinkerton detectives, L. P. Whitfield and W. D. McWorth, became suspicious. According to Leo Gottheimer, a National Pencil Company salesman, the two detectives visited the factory on May 16, 1913, a little more than two weeks after the murder, and asked “those present if they knew whether Jim Conley could write.” At McWorth’s request Gottheimer went over to the “Tower,” the county jail where Frank was being held, to ask Frank. The answer was definitive: “Yes, I know he can write, I have had notes from him asking me to lend him money…”