Well, here are the Omaha municipal codes that seem to have been broken:
http://www.municode.com/Resources/gateway.asp?pid=10945&sid=27Sec. 20-195. Possession or transportation of firearms.
(a) It shall be unlawful for any person to
knowingly or purposely transport in any conveyance or in any other manner, or to possess off his own premises, any rifle, shotgun, air gun, air rifle, paint ball gun or machine gun unless the same is unloaded and contained in any enclosed gun case, or unloaded and broken down. The removal of the bolt from any such firearm or carrying the same in a holster type gun case without further breaking down such firearm shall not be deemed to be in compliance with the requirements of this section.
(b) The provisions of this section shall not be applicable to:
(1) Authorized law enforcement officers;
(2) The armed forces of the United States, including ROTC units and the National Guard in the performance of their duties;
(3) The carrying of unloaded and uncased rifles in parades or using rifles in ceremonials;
(4) The possession of rifles, machine guns, or shotguns at shows or exhibits; or
(5) Any other lawful use, purpose or activity, including but not limited to skeet and trap shooting, target shooting at rifle ranges, hunter safety instruction conducted by qualified instructors, when such do not endanger public safety or are detrimental to public welfare; provided, however:
a. The prior approval of the police chief shall have been obtained for such use, purpose or activity; and
b. With respect to skeet and trap shooting ranges located or to be located in public parks, the final determination of the safety of the same shall be made by the city council.
(Code 1980, ? 20-195; Ord. No. 33113, ? 3, 11-23-93; Ord. No. 33757, ? 7, 12-19-95; Ord. No. 36361, ? 2, 8-19-03)
Cross references: Firearms exhibitions, ? 19-383 et seq.
Sec. 20-192. Carrying concealed weapon.
It shall be unlawful for any person except an authorized law enforcement officer purposely or knowingly to carry a weapon
concealed on or
about his person. On or after January 1, 2007, any person possessing a lawful permit issued by the State of Nebraska authorizing the carrying of concealed handguns shall be permitted to carry such a concealed handgun in the City of Omaha as permitted by state law.
(a) In any violation where the concealed weapon is a concealable firearm, any sentence shall include a minimum jail sentence of 30 days.
(b) Any person convicted under this section where the concealed weapon is not a concealed firearm shall be punished as provided in section 1-10.
(Code 1980, ? 20-192; Ord. No. 37432, ? 1, 7-18-06; Ord. No. 38294, ? 1, 11-18-08)
Evidently, a blanket does not suffice to be rifle case.