Law enforcement can conduct a Terry stop using reasonable suspicion - very constitutional.

Louisiana Art. 215.1. Temporary questioning of persons in public places; frisk and search for weapons

A. A law enforcement officer may stop a person in a public place whom he reasonably suspects is committing, has committed, or is about to commit an offense and may demand of him his name, address, and an explanation of his actions.

B. When a law enforcement officer has stopped a person for questioning pursuant to this Article and reasonably suspects that he is in danger, he may frisk the outer clothing of such person for a dangerous weapon. If the law enforcement officer reasonably suspects the person possesses a dangerous weapon, he may search the person. (Note that frisk is not the same as a search. An officer is limited in exactly how they frisk the suspect.)

C. If the law enforcement officer finds a dangerous weapon, he may take and keep it until the completion of the questioning, at which time he shall either return it, if lawfully possessed, or arrest such person.

D. During detention of an alleged violator of any provision of the motor vehicle laws of this state, an officer may not detain a motorist for a period of time longer than reasonably necessary to complete the investigation of the violation and issuance of a citation for the violation, absent reasonable suspicion of additional criminal activity. However, nothing herein shall prohibit a peace officer from compelling or instructing the motorist to comply with administrative or other legal requirements of Title 32 or Title 47 of the Louisiana Revised Statutes of 1950.
Added by Acts 1968, No. 305, §1. Amended by Acts 1982, No. 686, §1; Acts 1983, 1st Ex. Sess., No. 32, §1; Acts 1997, No. 759, §3, eff. July 10, 1997.