This, amongst other considerations to be named, had evidently cooled Arnold's ardor in the prosecution of the plot, and was the cause of his disposition to withdraw from it. The probabilities are that his parents and friends suspecting that his intimacy with Booth foreboded evil, and probably suspecting something of his purpose, had so earnestly remonstrated with him as to cause him to stagger or falter in his purpose, and made him anxious for an excuse for breaking with Booth. He perhaps began to regard Booth's plan as quixotic and impracticable, full of hazard, and not likely to succeed. In fact, he stated that he so told Booth at this meeting. He was evidently restive, and thought it had been put off too long to effect the end contemplated. It does not appear to have been from any awakening of his moral nature that he faltered, neither from cowardice that he weakened; and so he failed to purge himself of complicity in Booth's guilt. But there was sufficient evidence of his desire to withdraw from any part in the execution of Booth's present purposes to extenuate his guilt in a measure, at least, in the judgment of the Commission. _Arrest of O'Laughlin._ Arnold's letter to Booth on the 27th of March, which was found in Booth's trunk, together with evidence gathered up on every hand as the investigation proceeded, led to the arrest of Michael O'Laughlin at the house of his brother-in-law, in Baltimore, on Monday, the 17th of April, the same day on which Arnold was arrested. When arrested he seemed to understand what it was for, not asking any questions about it. He had gone to Washington on the 13th and remained until Saturday, the 15th. On returning to Baltimore on Saturday night, he was met at the depot by his brother-in-law, who told him that he had been inquired for by detectives that evening. Being advised by the friend who had accompanied him to Washington and back to remain at his home, he said he would not be arrested at home, as it would kill his mother. Why was he expecting to be arrested? A man innocent of crime never fears or expects arrest. He went to the house of his brother-in-law and quietly awaited the issue. He even requested his brother-in-law to inform the officer of his whereabouts, thus seeming to court arrest. He had carefully thought the thing over, and concluded that the government would not be able to fix guilt upon him, and so he thought to have the benefit of a seeming willingness to be arrested, as presumptive proof of his innocence. He had gone to Washington on the 13th with three companions, ostensibly to see the parade and illumination in commemoration of the surrender of Lee's army, and to "have a good time," as his companions expressed it in their evidence in his behalf on his defense.