For example it could be argued that Lizzie knew Thursday afternoon was Bridget's day off. Perhaps Bridget would prepare dinner, wash the dishes and go out~perhaps to a fabric sale~and Andrew could be dispatched while he napped after dinner. That would be premeditation with a workable plan.
Looking at Bridget's trial testimony it seems the note first comes up just after Lizzie asks her father about the mail. Q: What did she say if anything to her father? A:(She asked about the mail and there were somethings I didn't understand)"...but I heard her tell her father that Mrs. Borden had a note and gone out." It is a bit later that Lizzie mentions the fabric sale to Bridget with the admonition to lock the door because Mrs. B. had gone out on a sick call and Lizzie says she might go out also.
As I understand it possibly only Andrew knew Uncle John was coming back for dinner, though he may have told Abby who was already dead by the time Andrew came back anyway. One could suppose that in the things Bridget didn't hear, that after Lizzie told Andrew about the note implying Abby would not be home for dinner, Andrew might have made a comment that Abby wouldn't be gone all that long because Uncle John was expected for dinner.
If Lizzie had a murderous plan this would surely have been an "Oh expletive" moment. (something far stronger than Bridget's 'Pshaw', which I always assumed might have actually been one of those colorful Irish curses that start 'Jaysus, Mary and St. Joseph...', and that's why Lizzie laughed) One could suggest that's why Andrew was killed fairly quick after his last conversation with Lizzie, but if Andrew had mentioned Uncle John coming for dinner would Lizzie have dared another murder at that time when her uncle could arrive at any moment? If Andrew didn't mention Morse coming back, and if Lizzie had a well thought out plan which included directing Bridget to a sale down town, then leaving the house herself, why didn't she follow through on that time frame?
Whether or not a well thought out plan that included Andrew could have ever been accomplished is another consideration. It would depend on Bridget either being gone or upstairs in her room, neither possibility being certain. (Bridget may simply have decided to sit under the shade of the pear tree for an indeterminate amount of time, eating pears that afternoon.) To argue that Lizzie killed Andrew on the spur of the moment at the time when he was killed indicates she was willing to risk Bridget coming back downstairs at any time. If so, would she have killed Bridget too? Or would the argument be that Lizzie was insane and the murderous passion overcame her judgement?
The time and time frame around Andrew's death has always bothered me. It's tight for Lizzie or an intruder, yet someone did it. Lizzie knew all the risks and since she wasn't totally insane she also had to have some idea how she would handle various possibilities like Bridget coming downstairs at the wrong time, Bridget not leaving on her day off, Andrew remaining alert and active all afternoon, or going out again before he could be killed. With as little interest as Lizzie seemed to have in the affairs of the household, she would not have necessarily known if any guests might be expected. It has been written though I don't have the source, that people who had business with Andrew knew they could reach him at home around 11:00 am, after he had returned to the house. Surely Lizzie knew this was a possibility though I suppose the locked front door would simply encourage such visitors to go away if they were ignored.
(I probably could have written this better and made a few more points but right in the middle of my writing it sounded like something attacked one of my barn cats. Have had intermittent predator grabbing barn cat problems this winter, but all the predators should be back in the hills by now. Anyway my dog & I had to go out and check around. We didn't find anything but I am distracted. Perhaps there is a murder mystery in the feline population.
