United States v. Martinez-Hernandez, 422 F.3d 1084 (10th Cir. Sept. 2, 2005) (California conviction for possession of a weapon, in violation of Penal Code 12020(a)(1) cannot be considered a "firearms offense" where the record of conviction did not specify the weapon, even though the police report indicated that the weapon involved was a sawed-off shotgun).