Mr. Schmidt was at his home at 555 Ninth avenue last evening. He told our reporter who called that he saw his sister for the last time on the Sunday before the murder. Previous to that, upon the information from Louis Groth that she was living with Kettler in Second avenue, he saw her there, and remonstrated with her. He also had a talk with Kettler, who, however, said nothing of any proposed marriage. He said, however, that he knew Muller. Muller told Schmidt that he didn’t know Kettler. Schmidt says that when his sister Mina called at his house on Sunday she got a bank book containing $40 which he had been keeping for her, and told him that she had sold her furniture, and had altogether $116. She was going to marry Kettler on Tuesday, May 3, and go with Kettler to Alsace, which was his former home. Her brother says he told her he did not want her to marry again while she had a husband, but she said she was determined to do so. Mr. Schmidt has a brother August, a musician, living at 49 Avenue A. and two sisters now living one of whom is married. Muller, he says, was attentive to the unmarried sister, and Mrs. Muller and he continually quarrelled about this intimacy. Their disputes were so violent as to attract the attention of the people in the house where they lived in Thirty-ninth street, and once Mr. Muller was badly whipped, it is reported, by some friends of Mrs. Muller. Muller and his wife were married in 1874, and lived for three and a half years in the house at 338 West Thirty-ninth street. Muller made cigars and kept a small store there. When he and his wife could stand each other no longer, said Mr. Schmidt, they separated, and Mrs. Muller for a while lived in a house in the same block. About three months previous to the murder she left the neighborhood and secured employment in the butcher shop of Moise Heahn in Third avenue. Muller sold his store out on April 1, and removed to his present place in Thirtieth street. Mr. Schmidt said that Kettler, after marrying his sister, undoubtedly led her to the lonely place of the murder for the sole purpose of killing and robbing her of the $116 which she had, and the gold watch and chain. As Mrs. Muller left her brother’s house on Sunday she said to the saloon-keeper on the ground floor, “I’ve got another man--a nice man now--and I’m all right again.” Kettler had been only seven months in this country. Attorney-General Stockton directed Mr. McGill to telegraph to the authorities at Havre, describing Kettler, and requesting his arrest on a charge of murder. Detective Edward Stanton was to sail for Europe on Saturday in pursuit of the murderer, but subsequent events proved this unnecessary, as the reader will learn by following this complete and dramatic recital. TRACKED AND ARRESTED. Wildly Declaring his Innocence, yet admitting that he was in Hoboken with the murdered woman--“She Led Me Astray”--A very Touching Scene with his Wife.