LOS ANGELES: A knife found buried at O.J. Simpson’s former estate has been ruled out as the murder weapon in the 1994 killing of the football star’s ex-wife and her friend, police said Friday. The knife with a five-inch blade was found more than a dozen years ago by a construction worker at the estate where Simpson lived. The man gave the knife to a retired Los Angeles police officer who was working as a security guard at a nearby film shoot. “We have ruled out that the knife is connected to the murder,” officer Rosario Herrera, of the Los Angeles Police Department, told AFP. “The investigation remains open.” Police recently conducted testing on the knife, leading to speculation that it could provide a new lead in the slaying of Simpson’s ex-wife Nicole Brown Simpson and her friend Ron Goldman. The pair were found stabbed to death outside her home and the former American football star was charged with murder and endured one of the most highest-profile trials in US legal history. Simpson was acquitted in the case but is now serving time in prison for an armed robbery and kidnapping in Las Vegas.