The Domestic Violence Offender Gun Ban, the Lautenberg Amendment, prohibited anyone previously convicted of a misdemeanor or felony crime of domestic violence from shipment, transport, ownership and use of guns or ammunition. This was ex post facto, in the opinion of Representative Bob Barr. This law also prohibited the sale or gift of a firearm or ammunition to such a person. It was passed in 1996, and became effective in 1997. The law does not exempt people who use firearms as part of their duties, such as police officers or military personnel with applicable criminal convictions; they may not carry firearms.