From Wikipedia:

Jason Simpson Theory

Another theory that has been put forth is that Simpson's son, Jason Simpson, committed the murders. This is the central theory of a book by William Dear titled O.J. is Guilty, But Not of Murder (ISBN 0-9702058-0-5). This book attempts to explain Simpson's incriminating behavior and the incriminating evidence, and also presents an alternative theory of how the murders took place. Among the circumstances Dear, a former detective, claims in the book to support his theory are:

    * Jason Simpson had developed a crush on Nicole Brown Simpson, and was angry at the lifestyle she was involved in, which included drug use.

    * Jason Simpson had been known to go into violent epileptic rages and would often not remember what he had done.

    * Jason was a chef-in-training and would always carry his knife set with him. These knives were more than capable of committing the murders, and inflicting the type of wounds found on the victims.

    * Jason had no alibi the night of the murders, as the restaurant he was working at was closed that night. He stated he was cooking in front of 200 people the night of the murders. However, the restaurant that he worked at during the murders could hold a maximum of 87 people at any one time. He also later stated in a civil deposition that he clocked out after the murders had taken place.

    * After committing the murders, Jason called Simpson to the crime scene. Simpson struggled with his son to take the weapons from him, thus providing the detectives with the gloves and the blood evidence that would be used at his trial. Dear also believes this is where O.J. received the cut on his hand that prosecuters said was inflicted during the murders.

    * O.J. tried to cover up the crime of his son because of the guilt O.J. felt as a result of being a neglectful father.