The murder investigation, chaotic and stumbling as it was, can be reconstructed from the four official judicial events in the Lizzie Borden case: The inquest, the preliminary hearing, the Grand Jury hearing, and the trial. Basically, a circumstantial case against Lizzie was developed without the precise identification of a murder weapon, with no incriminating physical evidence for example, bloodstained clothes and no clear and convincing motive. Also, the case against Lizzie was hampered by the inability of the investigators to produce a corroborated demonstration of time and opportunity for the murders.
Over the course of several weeks, investigators were able to construct a time-table of events covering the period of Wednesday, August 3, the day before the murders, through Sunday, August 7, the day that Miss Russell saw Lizzie burning a dress, an act that proved crucial at the inquest.
The investigation found that four events of significance occurred on August 3. The first was that Abby Borden had gone across the street to Dr. Bowen at seven in the morning, claiming that she and Andrew were being poisoned. Both of them had been violently ill during the night. Dr. Bowen told her that he did not think that her nausea and vomiting was serious, and sent her home. Later, he went across the street to check on Andrew, who ungraciously told him that he was not ill, and that he would not pay for an unsolicited house call. Bridget had also been ill that morning. No evidence of poisoning was found during the autopsies of Andrew and Abby.
The second was that Lizzie had attempted to buy ten cents worth of prussic acid from Eli Bence, a clerk at Smith's Drug Store. She told Bence that she wanted the poison to kill insects in her sealskin cape. Bence refused to sell it to her without a prescription. Two others, a customer and another clerk, identified Lizzie as having been in the drugstore somewhere between ten and eleven-thirty in the morning. Lizzie denied that she had tried to buy prussic acid, testifying at the inquest that she had been out that morning, but not to Smith's Drug Store, then changing her story by saying that she had not left the house at all until the evening of August 3.
Third, early in the afternoon, Uncle John Morse arrived. He was without luggage, but intended to stay overnight, so that he could visit relatives across town the next day. Both he and Lizzie testified that they did not see each other until after the murders the next day, although Lizzie knew that he was there.
Finally, that evening Lizzie visited her friend, Miss Alice Russell. According to Miss Russell, Lizzie was agitated, worried over some threat to her father, and concerned that something was about to happen. Lizzie returned home about nine o'clock, heard Uncle John and her parents talking loudly in the sitting room, and went upstairs to bed without seeing them.
The morning of the murder began with Bridget beginning her duties about 6:15. Uncle John was also up. Abby came down about seven, Andrew a few minutes later. They had breakfast. Lizzie remained upstairs until a few minutes after Uncle John left, at about 8:45. Andrew left for his business rounds around nine o'clock, according to Mrs. Churchill, the neighbor to the north. He visited the various banks where he was a stockholder, and a store he owned that was being remodeled. He left for home around 10:40, according to the carpenters working at the store.
Just before nine o'clock, Abby instructed Bridget to wash the windows while she went upstairs to straighten up the guestroom where Uncle John had spent the night.
Some time between nine and ten (probably 9:30) Abby was killed in the guestroom. She had not gone out. The note that Lizzie said Abby had received from a sick friend, asking her to visit, was never found, despite an intensive search. Lizzie said that she might have inadvertently burned it.
Andrew returned shortly after 10:40. Bridget was washing the inside of the windows. Because the door was locked from the inside with three locks, Bridget had to let Mr. Borden in. As she fumbled with the lock, she testified that she heard Lizzie laugh from the upstairs landing. However, Lizzie told the police that she had been in the kitchen when her father came home.
Mr. Borden, who had kept his and Mrs. Borden's bedroom locked since a burglary the year before, took the key to his bedroom off the mantle and went up the back stairs. Lizzie set up the ironing board and began to iron handkerchiefs. For a few minutes more, Bridget resumed washing windows.
Bridget went up to her room to lie down about 10:55. Andrew went to the couch in the sitting room for a nap. Lizzie went out into the yard, or to the barn, or to the barn loft, for twenty to thirty minutes. Where she had precisely gone was vague. She said that her purpose for going to the barn was to find some metal for fishing sinkers, since she intended to join Emma at Fairhaven and to do some fishing. When she returned at 11:10, she found her father dead.