GO 536.0420 - Chemical Restoration of Obliterated VINs

SACRAMENTO POLICE DEPARTMENT GENERAL ORDERS GO 536.04 Page 1 of 2 536.04 CHEMICAL RESTORATION OF OBLITERATED VEHICLE IDENTIFICATION NUMBERS 10-09-12 PURPOSE The purpose of this order is to establish procedures for chemical restoration of Vehicle Identifications (VIN) numbers. POLICY It shall be the policy of the Sacramento Police Department to establish a standard for conducting chemical restoration of VIN numbers. PROCEDURE A. GENERAL 1. This process shall be performed by Forensic Investigators in coordination with th e Office of Investigations Auto Theft Unit. a. When possible, Forensic Investigators shall perfo rm restorations accompanied by a uto theft investigators b. Auto t heft investigators may perform chemical restoration if Forensic Investigators are unavailable in order to expedite the investigation. 2. Restoration results shall be processed through the OOI Auto Theft Unit as soon as possible. B. SAFETY PRECAUTIONS WHILE PROCESSING Employees conducting chemical restoration of VIN numbers shall: 1. Use goggles or a face shield, and chemical resistant rubber gloves. 2. Use chemicals in well ventilated areas to avoid toxic fumes, or if unable to obtain adequate ventilation, use the half face respirator equipped with cartridge filters approved for organic vapor/acid, and gas. 3. Ensure all chemicals are labeled. 4. Ensure a neutral izing solution of baking soda and water is available. 5. Ensure personal eye wash is nearby. C. SUR ACE PREPARATION Individuals shall prepare the surface as follows: 1. Remove all paint, dirt, grease, etc., using an automotive degreaser, or a non -abrasive cleaning agent. a. Limit the use of scrapers when cleaning. The surface metal must be completely bare and smoothed to a mirror -like finish. b. Be careful to remove as little of the metal as possible 2. Photograph the area before and after cleaning. Include close ups of an y discernable numbers. 3. Document any discernable numbers. D. ETCHING SOLUTIONS 1. Employees shall use the following solutions when chemically restoring obliterated VIN numbers. a. Nitric acid - Use a diluted solution of 25% acid to 75% water. Used for aluminum surfaces. ALWAYS ADD ACID TO THE WATER, NOT THE WATER TO ACID. b. Fry's solution - A hydrochloric acid based compound with cupric ammonium chloride and water. Use a diluted solution of 25% acid to 75% water. Used on steel or aluminum surfaces. ALWAYS ADD ACID TO THE WATER, NOT THE WATER TO ACID. 2. The chemicals shall be mixed in a glass Pyrex measuring cup and be used for the chemical processing. ALWAYS ADD THE ACID TO THE WATER, NOT THE WATER TO ACID. E. CHEMICAL PROCESSING 1. CAUTION: Numbers will often appear one (1) at a time and then disappear before another number can be restored. When possible, photograph the numbers as they appear. SACRAMENTO POLICE DEPARTMENT GENERAL ORDERS GO 536.04 Page 2 of 2 2. The following procedures shall be used for the surface indicated: Aluminum surfaces a. Use a diluted solution of either Nitric Acid or Fry's solution . b. Apply the solution to the prepared surface using a cotton ball or synthetic cotton ball held in surgical forceps. (1) The application should be in a sweeping motion along the surface in the same direction. Continue this application until the obliterated number is restored. (2) Alternate the appl ication with a water spray which helps remove residue and highlight the restored numbers. 3. The restored numbers can be preserved by spraying the metal surface with oil or silicone. Steel surfaces a. Use a diluted form of Fry's solution. b. The "ELECTROLYTIC PROCE SS" is recommended to enhance the restoration on steel surfaces. NOTE: If the subject vehicle has a battery connected, disconnect the battery by removing the negative ( -) cable first, followed by removing the positive (+) cable before using the Electrolyt ic process. (1) Apply the solution in combination with electrical current (ELECTROLYTIC PROCESS). The electrical current serves as a catalyst for the acid and speeds up the etching. (2) The source of the electrical current shal l be 12 volts DC supplied by an automobile battery or battery charger. (3) The electrical current is applied directly to the surface being processed by two (2) wires, #12 or #14 gauge. a) One (1) wire is attached to the ground, (negative ( -) terminal and then to the surface. b) The second wire is attached to the hot lead, (positive (+))terminal at one end and the other end is attached to an alligator clip type clamp to which the synthetic cotton -like ball is attached. (4) Once the cotton -like ball is attached to the clip, it is dipped/soaked in the etching solution and then swabbed across the surface as above until the numbers are restored. Alternate the swabbing with sprays of water to help remove residue and highlight the numbers c. As above, the restored numbers can be preserved by spraying the surf ace with oil or silicone. F. CLEAN -UP 1. Contaminated cotton -like balls shall be wrapped in newspaper and disposed of in an outdoor industrial trash receptacle. 2. Unused chemicals shall be returned to