EMILIO M. GARZA, Circuit Judge:
Pro se plaintiff Kenneth J. Masat (“Ma-sat”) appeals his conviction for tax evasion, alleging that he is entitled to a new trial due to improper voir dire procedure, discriminatory use of peremptory challenges, incorrect jury instructions, incorrect denial of a request for disclosure of alleged exculpatory materials, incorrect evidentiary rulings and quashing of subpoenas, and lack of subject matter jurisdiction and personal jurisdiction. Finding no error, we affirm.
I.
Masat was a pilot with Continental Airlines from 1979 through 1981. During these years, although he had a gross income that required him to file an income tax return,
Masat failed to file his income tax returns.
Masat submitted numerous W-4 forms to Continental Airlines in order to limit the amount of income tax withheld from his wages. He maintains, however, that there was nothing false about those W-4 forms. Masat used various methods to conceal his income and assets: he claimed he was a minister and, thus, exempt from taxes; he also used false social security numbers and false names to conceal assets. Masat was tried and convicted by a jury for income tax evasion for the years 1979 through 1981. Masat now appeals
and seeks a new trial.
II.
A.
Masat argues that the district court failed to use voir dire procedures that would reasonably disclose whether jury panel members were prejudiced as a result of being “the subject of any audit or other tax investigation” by the Internal Revenue Service.
See
26 U.S.C.A. § 6103(h)(5) (West 1989 & Supp.1991).
This court reviews the district court’s handling of procedures set forth in 26 U.S.C.A. § 6103(h)(5) to determine whether the procedure followed by the district court was prejudicial to Masat.
See Masat I,
896 F.2d at 95. Even if this court finds error, this court evaluates that error to determine whether it is harmless.
Id.
Section 6103(h)(5) of Title 26 of the United States Code provides that:
In connection with any judicial proceeding described in paragraph (4) to which the United States is a party, the Secretary shall respond to a written inquiry from an attorney of the Department of Justice ... involved in such proceeding or .any person ... who is a party to such proceeding as to whether an individual who is a prospective juror in such proceeding has or has not been the subject of any audit or other tax investigation by the Internal Revenue Service. The Secretary shall limit such response to an affirmative or negative reply to such inquiry.
Prior to his second trial, Masat requested a list of prospective jurors so that he could make an inquiry pursuant to section 6103(h)(5). The district court ordered that Masat be provided with the list. Masat received the list and sent it to the Secretary of Treasury, and the Secretary of Treasury replied pursuant to section 6103(h)(5). However, prior to voir dire, defendant told the district court that the list only went back five years, despite the fact that section 6103(h)(5) contains no time limitation on the information to be provided by the Secretary of Treasury.
Masat argues that the information obtained from the Secretary of Treasury pursuant to section 6103(h)(5) was incomplete and that he was prejudiced by the district court’s failure to strike the jury panel, or continue the jury selection until he obtained complete information.
The Government contends that Masat was not prejudiced, and that the district court allowed Masat ample opportunity to explore any alleged prejudices.
The Government’s arguments are persuasive in light of this court’s reasoning in
Masat
7, 896 F.2d at 95. In
Masat I,
Masat received the names of potential jurors in time to write to the Secretary of Treasury, but he did not receive complete information on all of the jurors in time for trial. Masat sought a continuance to get the additional information, but that motion was denied. However, on voir dire, the district court did ask the jurors if they had been the subject of an audit or controversy with the I.R.S. On appeal, this court stated that “[a]l-though the district court should have allowed Masat time to discover the juror information from the Secretary, any error was not prejudicial, for the jurors were asked the relevant questions by the trial judge.”
Id.
Thus, this court found that any error in failing to grant Masat a con
tinuance to obtain further information was harmless.
Id.
In the present case, the district court asked the venirepersons questions regarding any potential prejudice they might have toward the Government or Masat as a result of the prospective jurors’ prior interactions with the I.R.S. The district court also allotted the Government and Masat time to ask additional questions about any such association with the I.R.S. Masat has not shown how he was prejudiced by the venire process or by the inclusion of any specific venireperson onto the jury. As the district court asked the prospective jurors probing and specific questions regarding any past association with the I.R.S., this court finds that any error resulting from the Secretary of Treasury’s limited list was harmless.
Id.
B.
Masat asserts that the district court improperly denied his “Rejection of Jury” motion, which was based on the Government’s alleged discriminatory use of peremptory challenges. Masat’s argument is based primarily on
Batson v. Kentucky,
476 U.S. 79, 96-98, 106 S.Ct. 1712, 1723-24, 90 L.Ed.2d 69 (1986), in which the Court set forth a test to establish a prima facie case of discrimination because of the prosecutor’s use of peremptory challenges at a defendant’s trial. Defendant must show that: (i) he is a member of a cognizable racial group; (ii) the prosecutor has exercised peremptory challenges to remove people sharing the defendant’s race from the venire; and (iii) these facts and other relevant circumstances raise an inference that the prosecutor used the practice to exclude persons from the venire on account of their race.
Id.
Once the defendant makes this prima facie showing, the burden shifts to the Government to come forward with a race-neutral explanation for excusing the jurors in question.
Id.
The trial court must then determine if the defendant has established purposeful discrimination.
Id.
The Court also noted that a defendant’s objection to the prosecutor’s challenges must be timely.
Id.
at 99, 106 S.Ct. at 1725.
Both Masat and the Government agree that Masat did not object to the prosecutor’s challenges until the first day of trial— long after the unselected venirepersons had been dismissed.
In fact, Masat did not object until several weeks after the jury was chosen, sworn in, and the unselected venirepersons released. The Government contends that
Batson
does not apply because Masat’s motion in the district court was untimely. This court has stated that a
Batson
motion must be timely in order to be maintained.
Masat argues that he objected at such a late date because it was only then that he had enough time to examine the Government’s challenges. Unfortunately, the district court was not in a position to entertain Masat’s afterthoughts and therefore overruled his objections to the jury. The dis
trict court apparently made no findings regarding Masat’s
Batson
challenge, and Ma-sat apparently did not request that the district court make such
Batson
findings.
Because Masat offered no credible explanation for the last-minute nature of his motion,
Batson
does not provide him with a ground for reversal or remand. This court need not review the prosecutor’s use of peremptory challenge where objections to those challenges are raised long after the unselected venirepersons have been sent home.
See Thomas v. Moore,
866 F.2d 803, 804-06 (5th Cir.),
cert. denied,
493 U.S. 840, 110 S.Ct. 124, 107 L.Ed.2d 85 (1989) (explaining importance of timely objection for
Batson
claim).
C.
Masat maintains that the district court failed to properly instruct the jury regarding: (i) his church defense; (ii) his defense of reliance on professionals; and (iii) the essential elements of willfulness.
Trial judges have substantial latitude in tailoring their instructions if they fairly and adequately cover the issues presented in the case.
See United States v. Hunt,
794 F.2d 1095, 1097 (5th Cir.1986),
later proceeding,
688 F.Supp. 265 (N.D.Tex.1987),
later proceeding,
857 F.2d 1471 (5th Cir.1988),
post-conviction proceeding, appeal dismissed,
940 F.2d 130 (5th Cir.1991) (citations omitted). A district court’s refusal to deliver a requested instruction constitutes reversible error only if three conditions exist: (i) the requested instruction is substantively correct; (ii) the requested instruction is not substantially covered in the charge actually given to the jury; and (iii) the requested instruction concerns an important point in the trial so that the failure to give it seriously impairs the defendant’s ability to present a given defense effectively.
Id.; see also United States v. Molina-Uribe,
853 F.2d 1193, 1201 (5th Cir.1988),
cert. denied,
489 U.S. 1022, 109 S.Ct. 1145, 103 L.Ed.2d 205 (1989) (citation omitted);
United States v. Duvall,
846 F.2d 966, 971 (5th Cir.1988) (citations omitted). An abuse of discretion occurs only when the failure to give a requested instruction serves to prevent the jury from considering the defendant’s defense.
Hunt,
794 F.2d at 1097.
(i) Masat’s Church Defense
Masat sought to base a defense to tax evasion on the theory that he was a minister and therefore exempt from paying federal income taxes. Masat alleges that the district court abused its discretion in refusing to give the instructions he requested concerning this defense.
The Government maintains that the district court gave the jury an instruction which allowed it to determine whether the church in which Masat was a minister was in fact exempt under 26 U.S.C.A. § 501(c)(3) (West 1988 & Supp.1991). A section 501(c)(3) organization that is “operated exclusively for religious ... purposes” is exempt from taxation if no part of the net earnings inure to the “benefit of any private shareholder or individual,...”
United States v. Daly,
756 F.2d 1076, 1082-83 (5th Cir.),
cert. denied,
474 U.S. 1022, 106 S.Ct. 574, 88 L.Ed.2d 558 (1985). According to Masat, the instructions given were grossly incorrect regarding whether any part of the net earnings inured to his benefit. Masat argues that: the instructions dealing with the validity of his church that he proposed should have been given;
the district court’s instructions regarding the validity of W-4 forms was in error;
and that the court’s denial of an instruction regarding an I.R.S. publication called Circular E, Employer’s Tax Guide, was also in error.
The Government maintains that the jury instructions the district court gave were adequate.
The district court instructed the jury regarding exemptions for religious organizations and the federal income tax obligations of ministers.
Masat has failed to clearly
identify how the instructions he alleges should have been given were not substantially covered in the charge actually given to the jury, or concerned an important point in the trial so that the failure to give them seriously impaired the defendant’s ability to effectively present his defense based on his church activities. Accordingly, the district court did not abuse its discretion in failing to give Masat’s requested instructions.
(ii) Masat’s Defense of Reliance on Professionals
Masat urged a second defense to income tax evasion: reliance on advice from various professionals — Gordon Tyner, an attorney; Guy Curtis, an attorney; and Chris Noble, an accountant and attorney. He argues that despite the evidence regarding his reliance, the district court mistakenly refused to give his proposed instruction number 25.
Masat does not clearly articulate how he relied on these professionals. Ma-sat points to documents, such as letters and legal documents, which he claims indicate such reliance. It appears that over a period of years, including the years for which he was prosecuted, Masat had contact with these individuals. Such contact, however, does not necessarily indicate reliance on these professionals’ advice. To establish reliance as a defense, Masat must show that: (i) he relied in good faith on a professional and (ii) he made complete disclosure of all the relevant facts.
See United States v. Meyer,
808 F.2d 1304, 1306 (8th Cir.1987) (citations omitted);
United States v. Stone,
431 F.2d 1286, 1288-89 (5th Cir.1970), ce
rt. denied,
401 U.S. 912, 91 S.Ct. 879, 27 L.Ed.2d 811 (1971);
United States v. Conforte,
624 F.2d 869, 877 (9th Cir.),
cert. denied,
449 U.S. 1012, 101 S.Ct. 568, 66 L.Ed.2d 470 (1980) (citations omitted).
Masat has failed to establish reliance. Regarding Gordon Tyner, there is no evidence that Masat relied in good faith on any advice Gordon Tyner gave, nor any evidence that Masat disclosed all the facts regarding his claimed exempt status to Gordon Tyner. Similarly there is no evidence that Masat relied on advice rendered by Guy Curtis and Chris Noble. Masat’s strongest argument is that he spoke with these people, and that he has some documentation of these conversations. However, as the Government points out, although Masat had contact with these individuals, he did not fully disclose all the facts regarding his claimed exempt status to them, and, therefore, any such reliance was not in good faith. Masat’s ability to present his defense was not seriously im
paired. Accordingly, the district court did not abuse its discretion by not giving the reliance instruction.
(Hi) The Willfulness Instruction
Masat also contests the district court instructions regarding the essential elements of tax evasion under 26 U.S.C.A. § 7201.
To establish a violation of section 7201, the Government must prove beyond a reasonable doubt: (1) the existence of a tax deficiency; (2) an affirmative act constituting evasion or attempted evasion of the tax; and (3) willfulness.
See United States v. Kim,
884 F.2d 189, 192 n. 1 (5th Cir.1989) (citation omitted);
United States v. Chesson,
933 F.2d 298, 303-04 (5th Cir.1991), ce
rt. denied,
— U.S. —, 112 S.Ct. 583, 116 L.Ed.2d 608 (1991) (citations omitted). The Government argues that the district court properly instructed the jury on these elements. Masat alleges that his proposed instructions 1, 8, and 9 should have been given,
and he specifically questions the district court’s instruction regarding willfulness. The district court’s instructions, however, adequately set forth the law for the jury.
The term willful means a voluntary, intentional violation of a known legal duty.
See Chesson,
933 F.2d at 304 (citation omitted). The district court explained this term.
Masat’s main argument is that the district court should have instructed the jury that the Government must prove that he acted in bad faith or with evil intent. In
Cheek v. United States,
— U.S. -, 111 S.Ct. 604, 609-10, 112 L.Ed.2d 617 (1991),
on remand,
931 F.2d 1206 (7th Cir.1991), the Court similarly noted that willfulness simply means a voluntary, intentional violation of a known legal duty. The Court did not expressly adopt the bad purpose or evil motive language which Masat requested. Thus, the district court’s instruction was adequate and embodied the applicable law.
D.
Masat alleges that the district court erred in denying his motion for the disclosure of exculpatory materials, including Freedom of Information Act documents,
grand jury documents, and a special agent’s report.
Masat claims that these exculpatory materials were required to be produced pursuant to
Brady v. Maryland,
373 U.S. 83, 87, 83 S.Ct. 1194, 1196-97, 10 L.Ed.2d 215 (1963), in which the Court stated that the prosecution’s suppression of evidence favorable to an accused upon request violates due process where the evidence is material either to guilt or punishment. Although the
Brady
rule requires a prosecutor to disclose evidence favorable to an accused that, if suppressed, would deprive him of a fair trial,
this court applies a strict standard of materiality.
See United States v. Medel,
592 F.2d 1305, 1317 (5th Cir.1979) (citations omitted). Thus, this court looks to see if the alleged exculpatory evidence is materially favorable to Masat as to guilt, punishment, or both.
Id.
Masat argues that certain Freedom of Information Act documents should have been disclosed to him because the documents would have allowed him to present other defenses and prevent the Government from presenting its best case. Masat alleges that many of these documents were likely obtained by the Government illegally. Although he does not explicitly say so, his argument for the production of the grand jury documents and special agent's report appears to be based on similar grounds.
The Government argues that the Freedom of Information Act documents were not exculpatory and that Masat had access to these documents by other means. Regarding the grand jury documents, the Government claims that Masat’s request was overly broad and that these documents did not contain anything material to Ma-sat’s guilt or punishment. The Government maintains that the special agent’s report was not material because any information the report contained could have been produced by other means.
Although the district court apparently did not conduct an in camera inspection of the alleged
Brady
documents, Masat has not adequately shown how the documents were material to his defense, how the documents’ production would have changed the outcome of the case, or that the documents’ failure to be produced has undermined the confidence in the integrity of the outcome of his trial.
See, e.g., United
States v. Bagley,
473 U.S. 667, 677-78, 105 S.Ct. 3375, 3381, 87 L.Ed.2d 481 (1985),
on remand,
798 F.2d 1297 (9th Cir.1986),
later proceeding,
659 F.Supp. 223 (W.D.Wash. 1987),
aff'd in part and rev’d in part,
837 F.2d 371 (9th Cir.1988),
cert. denied,
488 U.S. 924, 109 S.Ct. 304, 102 L.Ed.2d 323 (1988);
Hughes v. Hopper,
629 F.2d 1036, 1038-40 (5th Cir.1980),
cert. denied,
450 U.S. 933, 101 S.Ct. 1396, 67 L.Ed.2d 367 (1981).
E.
Masat also maintains that the district court abused its discretion by quashing subpoenas to Government employees and in precluding the admission of evidence.
(i) Quashing of Subpoenas/Witness Recall
The decision whether to grant a request for a subpoena rests within the district court’s discretion.
See United States v. Johnson,
495 F.2d 1097, 1102 (5th Cir.1974) (citations omitted). A district court does not abuse this discretion when it quashes a subpoena seeking irrelevant or immaterial information.
Id.
Masat had a subpoena duces tecum served on three Government witnesses: I.R.S. District Director Gary Booth, and I.R.S. Austin Service Center employees Carolyn Wunneberger and Mark O’Brien. The district court quashed these subpoenas, and Masat argues that the district court erred in quashing Booth’s subpoena because Booth would have shed light on questions regarding Masat’s church and his grounds for exemption. The Government maintains that the criteria for what constitute exemptions are legal criteria, and that only the judge is entitled to instruct the jury about the law. Masat also contends that Carolyn Wunneberger and Mark O’Brien should have been subpoenaed to testify about assessment procedures and possible recording errors. The Government argues that the testimony of Carolyn Wunneberger and Mark O’Brien would not have helped Masat negate his tax deficiency, given that Masat admitted he failed to file tax returns.
There is no indication in the briefs or record that Masat had any connection with these individuals he sought to subpoena, other than his desire to obtain information about I.R.S. procedures. The information Masat sought to obtain was either provided by other witnesses or explained in the district court’s jury instructions. Given the district court’s broad discretion to grant or deny a request for a subpoena,
see Johnson,
495 F.2d at 1102, there was no abuse of discretion in this case.
Masat also argues that the district court erred in refusing to allow him to recall agent Darrell Dillard to testify about an I.R.S. investigation of Masat’s church. Although Masat was not able to call Dillard as his witness, the record shows that after the Government questioned Darrell Dillard on direct examination, Masat extensively cross-examined him and later recross-examined him. Masat was thus able to question Darrell Dillard.
Moreover, there is no evidence that any subsequent witness gave an account which differed significantly from the testimony of Darrell Dillard on any crucial point. Under these circumstances, the court did not abuse its discretion and Masat’s argument has no merit.
See United States v. James,
510 F.2d 546, 551 (5th Cir.),
cert. denied sub. nom. Vasquez v. United States,
423 U.S. 855, 96 S.Ct. 105, 46 L.Ed.2d 81 (1975) (citations omitted) (trial judge has broad discretion in controlling the extent of direct and cross-examination).
(ii) Evidentiary Rulings
The district court has wide discretion in determining the relevance and materiality of evidence.
See United States v. Ashley,
555 F.2d 462, 465 (5th Cir.),
cert. denied sub. nom. Leveritte v. United States,
434 U.S. 869, 98 S.Ct. 210, 54 L.Ed.2d 147 (1977) (citation omitted);
United States v. Grimm,
568 F.2d 1136, 1138 (5th Cir.1978) (citation omitted). The district court’s evi-dentiary rulings will not be disturbed on appeal absent an abuse of discretion.
Id.
Masat questions the district court’s exclusion of: (1) a 1985 document from the
National Commodity and Barter Association that would allegedly show he was entitled to a tax refund; (2) the testimony of an accountant, Dan Unger, who would testify that Masat was entitled to a refund; (3) a 1987 opinion letter from attorney Guy Curtis about Masat’s tax obligations; (4) the testimony of former I.R.S. employee Paul DesFosses who allegedly made an administrative determination that Masat was not required to file a tax return for 1979; and (5) a letter from the I.R.S. to the Universal Life Church in Modesto, California, regarding the church’s tax exempt status.
The Government’s response is that: (1) the National Commodity and Barter Association evidence was prepared after the period for which Masat was prosecuted; (2) accountant Dan Unger was allowed to testify; (3) the opinion letter of attorney Guy Curtis was irrelevant; (4) the testimony of former I.R.S. employee Paul DesFosses was irrelevant, and (5) the letter to the Universal Life Church in Modesto California was irrelevant. The district court agreed with these contentions, and excluded the evidence.
Masat’s briefs and the record fail to show that the district court abused its wide discretion in its evidentiary rulings regarding these matters. The record indicates that the district court was simply attempting to manage the trial by eliminating cumulative and irrelevant proffered evidence.
See
FED.R.EVID. 403 and 611(a). These circumstances do not constitute an abuse of discretion.
F.
Finally, Masat alleges that the district court lacked subject matter jurisdiction over this action and personal jurisdiction over him. We disagree. As the Government correctly notes, district courts have original jurisdiction of offenses against the laws of the United States pursuant to 18 U.S.C.A. § 3231.
See United States v. McCarty,
665 F.2d 596, 597 (5th Cir.),
cert. denied,
456 U.S. 991, 102 S.Ct. 2273, 73 L.Ed.2d 1287 (1982). It follows that district courts have jurisdiction over Title 26 offenses.
See United States v. Przybyla,
737 F.2d 828, 829 (9th Cir.1984),
cert. denied,
471 U.S. 1099, 105 S.Ct. 2320, 85 L.Ed.2d 839 (1985) (citations omitted).
As for Masat’s personal jurisdiction contention, the basis of this argument is not clear. Masat provides no case law nor cogent analysis to support this contention. Masat’s brief states he is a “non-citizen” and a “non-resident.” More specifically, Masat claims the district court lacked personal jurisdiction over him because he is a “freeman.” In light of the fact that Masat was indicted for tax evasion, appeared before the district court, and has offered this court no support for his lack-of-personal-jurisdiction contention, we find his argument frivolous.
See Anders v. State of California,
386 U.S. 738, 747, 87 S.Ct. 1396, 1400, 18 L.Ed.2d 493 (1967) (frivolous appeal is one without arguable merit);
United States v. Schmitt,
784 F.2d 880, 882 (8th Cir.1986),
habeas corpus proceeding,
752 F.Supp. 306 (D.Minn.1990),
aff'd,
938 F.2d 189 (8th Cir.1991),
cert. denied,
— U.S. —, 112 S.Ct. 592, 116 L.Ed.2d 616 (1991) (appellants’ argument that the district court lacked personal jurisdiction over them because they were “natural freemen” is entirely frivolous).
III.
Accordingly, we AFFIRM.