United States Court of Appeals
                                                                 Fifth Circuit
                                                              F I L E D
                IN THE UNITED STATES COURT OF APPEALS           May 20, 2003

                        FOR THE FIFTH CIRCUIT              Charles R. Fulbruge III
                                                                   Clerk


                            No. 02-50603
                          Summary Calendar



UNITED STATES OF AMERICA,

                                     Plaintiff-Appellee,

versus

DAVID ALLEN LONG,

                                     Defendant-Appellant.

                        --------------------
           Appeal from the United States District Court
                 for the Eastern District of Texas
                    USDC No. EP-01-CR-1997-ALL-F
                        --------------------
Before HIGGINBOTHAM, SMITH, and CLEMENT, Circuit Judges.

PER CURIAM:*

     David Allen Long appeals his conviction and the sentence he

received for possession with intent to distribute marijuana after

the district court denied his motion to suppress evidence.         The

marijuana was seized after Long was stopped at an immigration

checkpoint.    This court reviews the district court's factual

findings regarding a motion to suppress for clear error and its

legal conclusions de novo.    United States v. Portillo-Aguirre,


     *
        Pursuant to 5TH CIR. R. 47.5, the court has determined
that this opinion should not be published and is not precedent
except under the limited circumstances set forth in 5TH CIR.
R. 47.5.4.
                                No. 02-50603
                                     -2-

, 651-52 (5th Cir. 2002).          When the facts are

undisputed, as they are in the instant case, questions such as

probable cause and reasonable suspicion are resolved as questions

of law.   

     The gist of Long’s argument is that once the agent

ascertained Long’s citizenship he could ask no further questions

and could not refer him to the secondary inspection area.           The

initial stop was constitutional.       United States v.

Martinez-Fuerte, 

, 562 (1976).          In United States v.

Machuca-Barrera, 

, 432 (5th Cir. 2001), this court

held that once the purpose justifying the stop has been served,

the detained person must be free to leave.

     Long likens his case to Portillo-Aguirre, where this court

held that a Border Patrol agent unlawfully extended an

immigration checkpoint stop of a commercial passenger 

.    However, the agent in that case lacked reasonable

suspicion of criminal activity before further detaining the

defendant.     

   Long ignores that the Border Patrol

agent in this case had reasonable suspicion of criminal activity

before he ascertained Long’s citizenship when he observed Long to

be nervous and observed the unusual circumstance that the air

conditioner was blowing hot air in a distracting manner.            See

(an agent at an immigration stop

may investigate non-immigration matters beyond the permissible

length of the immigration stop if the initial, lawful stop
                          No. 02-50603
                               -3-

creates reasonable suspicion warranting further investigation).

Given that the Border Patrol agent had reasonable suspicion to

further question Long and that the additional questions gave rise

to more reasonable suspicion, there was no Fourth Amendment

violation.

     AFFIRMED.