The retired officer held on to the knife for years, only turning it over to the LAPD in January.
The Los Angeles Police Department’s elite Robbery Homicide Division is investigating the knife, according to The Los Angeles Times. The paper reports that the investigation is in its early stages.
Simpson was charged in their murders, but found not guilty on Oct. 3, 1995.
Simpson is currently serving a prison sentence for his role in a 2007 robbery of a memorabilia dealer at a Las Vegas hotel.