Off-duty police officers
The Law Enforcement Officers Safety Act (LEOSA), which was intended to entitle qualified law enforcement officers to carry weapons nation-wide, does not provide any exceptions to Federal Law per 18 U.S.C. § 926B. Although the GFSZA does provide an exception for a law-enforcement officer performing their official duties, it does not provide any protection for an off-duty officer. An off-duty LEOSA qualified officer is unable to legally travel within one-thousand (1000) feet of any K-12 school while armed unless he/she has a valid carry license issued by that state.
please add to my post - from Wikipedia as the source