There is much debate over whether or not Lizzie Borden murdered her father and stepmother in 1892. The motive for the murders was said to be a difference of opinion between her, her sister and their father over how his estate was to be divided after his death. Lizzie was arrested a week after the murder but due to the lack of evidence against her (the existence of a murder weapon and lack of forensics) she was subsequently acquitted ten months later. http://www.ask.com/wiki/Lizzie_Borden
No one really knows the real reasons behind why Lizzy Borden killed her parents or even if she was the actual murderer. During her trial many of the witnesses contradicted each others statements. Some say it was over money, others claim it was because she was caught having an affair with her maid.
One of the speculated reasons presented in court for Lizzie Borden’s motive in killing her father is the alleged plan of her father to change his last will in favor of her step-mother rather then his own children. However, this was not sufficient to charge her of the crime because she was later on acquitted. Learn details of the case, visit http://www.prairieghosts.com/lizzie.html.
It seems that Lizzie Borden may have killed her parents because she was having issues with her father. There were properties that he wanted to give away to other family members, and he killed all of her pigeons. She was not convicted of the murders. For more information visit: http://www.ask.com/wiki/Lizzie_Borden#Murders