If the facts were presented as is I could see Emma doing it. However, there is stronger evidence that the maid (Bridget Sullivan) was responsible for the murders. In his book "Lizzie Borden The Untold Story," Edward D. Radin examined the trial transcripts and notes that Bridget's testimony had a few discrepancies and her actions on the day of the murders were quite suspect. Her motive? Mrs. Borden told her to wash the windows inside and out on the hottest day of the year. It was suggested that she later pleaded with Mrs. Borden for a postponement but was refused (Mr. Borden was home during this second conversation and was killed to eliminate him as a witness against her). All in all, this was a very interesting theory...but until positive evidence shows up that's all we will ever have.