Each state and local law enforcement agency shall submit to the Department of Public Safety and the Department of Motor Vehicle Safety the original document of any accident report prepared by such law enforcement agency or submitted to such agency by a member of the public. A law enforcement agency may transmit the information contained on the accident report form by electronic means, provided that the department has first given approval to the reporting agency for the electronic reporting method utilized. The law enforcement agency shall retain a copy of each accident report. All such reports shall be submitted to the department not more than 15 days following the end of the month in which such report was prepared or received by such law enforcement agency.