                    FOR PUBLICATION
  UNITED STATES COURT OF APPEALS
       FOR THE NINTH CIRCUIT

UNITED STATES OF AMERICA,                       No. 03-30434
                Plaintiff-Appellee,                D.C. No.
               v.                               CR-03-00086-
SHANE A. MASSEY,                                   aka-RRB
             Defendant-Appellant.
                                                 OPINION

        Appeal from the United States District Court
                 for the District of Alaska
        Ralph R. Beistline, District Judge, Presiding

                   Argued and Submitted
           February 17, 2005—Seattle, Washington

                     Filed August 15, 2005

      Before: Betty Binns Fletcher, Ronald M. Gould,
    Circuit Judges, and Samuel P. King,* District Judge.

                    Opinion by Judge Gould




   *The Honorable Samuel P. King, Senior United States District Judge
for the District of Hawaii, sitting by designation.

                               10659
                 UNITED STATES v. MASSEY            10661


                       COUNSEL

Mary C. Geddes, Assistant Federal Defender, Anchorage,
Alaska, for the defendant-appellant.

Eileen J. O’Connor, Assistant Attorney General, Robert E.
Lindsay, Alan Hechtkopf, Brian Galle, Attorneys, Tax Divi-
sion, Department of Justice, Washington, DC, for the
plaintiff-appellee.
10662               UNITED STATES v. MASSEY
                           OPINION

GOULD, Circuit Judge:

   Defendant-appellant Shane A. Massey was convicted of
one count of corruptly endeavoring to impede the administra-
tion of the tax laws, in violation of I.R.C. § 7212(a), and three
counts of willful failure to file income tax returns, in violation
of I.R.C. § 7203. Massey challenges his conviction and sen-
tence, arguing: 1) that he was deprived of his Sixth Amend-
ment right to counsel; 2) that the district court erred in
instructing the jury on the element of willfulness under § 7203
and on the omnibus clause of § 7212(a); and 3) that his sen-
tence violated his Sixth Amendment right to have all facts
used to enhance his sentence found by a jury beyond a reason-
able doubt. We affirm his convictions and remand for the dis-
trict court to consider resentencing in light of United States v.
Booker, 125 S. Ct. 738, 769 (2005), and United States v. Ame-
line, 409 F.3d 1073, 1084-85 (9th Cir. 2005) (en banc).

   Massey did not file accurate federal income tax returns for
tax years 1995 through 2001. When contacted by the Internal
Revenue Service (IRS) regarding his non-compliance with the
Internal Revenue Code, Massey threatened to sue the IRS and
its agents, told the IRS that he planned to charge it $500,000
for each “unauthorized” use of his name, and demanded that
the IRS cease efforts to subpoena his bank accounts. The
United States charged Massey with one count of corruptly
endeavoring to impede the administration of the tax laws, in
violation of I.R.C. § 7212(a), and three counts of willful fail-
ure to file income tax returns, in violation of I.R.C. § 7203.

   Before trial, the magistrate judge and the district court
informed Massey of the charges against him, the maximum
penalty for each charge, his right to counsel, including a
court-appointed attorney, and the disadvantages of proceeding
to trial pro se. Although Massey demanded his Sixth Amend-
ment right to the “assistance of counsel,” he repeatedly
                       UNITED STATES v. MASSEY                      10663
asserted, through letters and in-court statements, that he
would not accept retained counsel, court-appointed counsel or
standby counsel. Massey also thwarted the district court’s
attempts to provide him with standby counsel and court-
appointed counsel. At trial, Massey represented himself, was
convicted on all counts, and received a 41-month sentence in
accord with the U.S. Sentencing Guidelines. Massey appeals
on three grounds.

   [1] First, Massey argues that he did not validly waive his
Sixth Amendment right to counsel.1 We disagree. The record
as a whole indicates that Massey understood the charges
against him, the statutory penalties associated with these
charges, and the dangers and disadvantages of self-
representation. Lopez v. Thompson, 202 F.3d 1110, 1117 (9th
Cir. 2000) (en banc); United States v. Balough, 820 F.2d
1485, 1487 (9th Cir. 1987). Massey attempted to hinder his
trial by declining every constitutionally recognized form of
counsel while simultaneously refusing to proceed pro se. A
defendant may not abuse the Sixth Amendment in this way:
tactics such as those employed by Massey amount to an
unequivocal waiver of the right to counsel. United States v.
Kienenberger, 13 F.3d 1354, 1356 (9th Cir. 1994); United
States v. Hardy, 941 F.2d 893, 896-97 (9th Cir. 1991).

   [2] Second, Massey contends that the district court erred in
instructing the jury on 1) the element of willfulness in § 7203,
and 2) the omnibus clause of § 7212(a).2 We reject these argu-
  1
     Massey further argues that the magistrate judge did not have jurisdic-
tion to conduct an inquiry pursuant to Faretta v. California, 422 U.S. 806
(1975). 28 U.S.C. § 636; Peretz v. United States, 501 U.S. 923, 932-36
(1991); Gomez v. United States, 490 U.S. 858, 863-75 (1989). We need
not reach this question because we conclude that the record as a whole
demonstrates that Massey knowingly, intelligently and unequivocally
waived his right to counsel.
   2
     We review a district court’s formulation of jury instructions for an
abuse of discretion. United States v. Shipsey, 363 F.3d 962, 966 n.3 (9th
Cir. 2004). We review de novo whether a jury instruction misstates a
material element of a statute. Id.
10664              UNITED STATES v. MASSEY
ments. With respect to § 7203, the district court properly
instructed the jury that a disagreement with the Internal Reve-
nue Code or a belief that the Code is unconstitutional does not
negate the element of willfulness. Cheek v. United States, 498
U.S. 192, 206-07 (1991). With respect to § 7212(a), the dis-
trict court correctly instructed the jury that “corruptly” means
“performed with the intent to secure an unlawful benefit for
oneself or another.” See United States v. Workinger, 90 F.3d
1409, 1414 (9th Cir. 1996). The law of this circuit establishes
that the government need not prove that the defendant was
aware of an ongoing tax investigation to obtain a conviction
under § 7212(a); it is sufficient that the defendant hoped “to
benefit financially” from threatening letters or other conduct.
United States v. Kuball, 976 F.2d 529, 531 (9th Cir. 1992).

   [3] Third, Massey challenges his sentence on the ground
that it was based upon facts, other than prior convictions, not
found by a jury beyond a reasonable doubt in violation of the
Sixth Amendment. Pursuant to United States v. Ameline, we
remand to the district court to allow it to consider whether it
would have imposed the same 41-month sentence on Massey
if the U.S. Sentencing Guidelines system had been advisory,
rather than mandatory. 409 F.3d at 1084-85; Booker, 125
S. Ct. at 769.

  AFFIRMED IN PART, REMANDED IN PART.
