No. 99-30932
                                -1-

               IN THE UNITED STATES COURT OF APPEALS
                       FOR THE FIFTH CIRCUIT



                            No. 99-30932
                        Conference Calendar



JOHN ROBERT NICOLAUS,

                                          Plaintiff-Appellant,

versus

MONISA L. THOMPSON, Assistant D.A. for
East Baton Rouge Parish,

                                          Defendant-Appellee.

                      --------------------
          Appeal from the United States District Court
              for the Middle District of Louisiana
                      USDC No. 99-CV-412-B
                      --------------------
                         April 11, 2000

Before WIENER, DeMOSS, and PARKER, Circuit Judges

PER CURIAM:*

     John R. Nicolaus, Louisiana prisoner # 84080, appeals from

the dismissal of his 42 U.S.C. § 1983 action for failure to state

a claim, pursuant to 42 U.S.C. § 1997e(e) and 28 U.S.C. § 1915A.

He asserts that Monisa L. Thompson, the assistant district

attorney who filed the respondent’s answer to his fourth petition

for state habeas relief, made allegations in her brief which she

knew to be false.   Specifically, he contends that Thompson’s

assertion that he committed the offense of conviction is


     *
        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that this opinion should not be published and is not precedent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. 99-30932
                                  -2-

fallacious because he, a former United States Marine, was

stationed in California at the time of the murder, which occurred

in Baton Rouge, Louisiana.

     In order to prevail on this claim, Nicolaus would have to

demonstrate that he is innocent of the murder of which he was

convicted.    Such a result would necessarily imply the invalidity

of Nicolaus’s conviction, which has not yet been overturned or

expunged.    Therefore, this claim is barred by the principle,

enunciated in Heck v. Humphrey, 

(1992), that no

cause of action exists under § 1983 for allegations which, if

proved, would imply the invalidity of an underlying conviction or

sentence until the underlying conviction or sentence is

overturned or otherwise invalidated.     

     This appeal is frivolous, and we dismiss it as such.      Howard

v. King, 

, 219-20 (5th Cir. 1983); 5TH CIR. R. 42.2.

The magistrate judge’s dismissal of Nicolaus’s complaint for

failure to state a claim and this court’s dismissal of the appeal

as frivolous count as two “strikes” for purposes of 28 U.S.C.

§ 1915(g).    See Adepegba v. Hammons, 

, 385-87 (5th

Cir. 1996).   If Nicolaus accumulates three “strikes” under

§ 1915(g), he will be barred from proceeding in forma pauperis in

any civil action or appeal filed while he is incarcerated or

detained in any facility unless he is under imminent danger of

serious physical injury.     See § 1915(g).   To avoid sanctions,

Nicolaus is cautioned to review any pending appeals to ensure

that they do not raise arguments that are frivolous.

     APPEAL DISMISSED; SANCTIONS WARNING ISSUED.