Steven Glick was convicted after a jury trial of eight counts of mail fraud, 18 U.S.C. § 1341 (1976), ^[1] and two counts of travel in interstate commerce to execute a scheme to defraud, 18 U.S.C. § 2314 (1976) ^[2] On appeal, Glick argues that the court improperly instructed the jury on the issue of fraudulent intent, and that he was denied effective assistance of counsel because his attor[*641] ney failed to conduct adequate pretrial investigation. We affirm.

I.

THE FACTS

Viewed in the light most favorable to the Government, see United States v. Petersen, 611 F.2d 1313, 1317 (10th Cir.1979), cert. denied, 447 U.S. 905, 100 S.Ct. 2986, 64 L.Ed.2d 854 (1980), the facts are briefly as follows. Reginald Chisholm, the mastermind of the fraudulent scheme, was described as a man of great charm and personal magnetism. He held himself out during 1975 and 1976 as a very wealthy person who could package and obtain loans for people seeking financing. He charged a nonrefundable front fee for this service. Chisholm told his victims that as part of his service he would guarantee the loans, and that his guarantee would carry weight with lending institutions because of his wealth. To support these representations, Chisholm showed his victims financial statements describing Chisholm’s personal wealth and that of three corporations he owned or controlled. These statements were prepared by Glick, a certified public accountant, and included letters by Glick declaring that the statements fairly presented the subject’s financial position in conformity with generally accepted auditing standards and accounting principles.

The principal asset of Chisholm and his corporations was his claim to mineral rights in limestone formations in National Forest lands. These rights had been transferred by Chisholm to one of his corporations, and then from corporation to corporation, each transfer resulting in an increased valuation of the mining claims.

Chisholm and Glick were indicted, and Chisholm pled guilty prior to trial. Chisholm had previously been convicted in a federal criminal proceeding in Portland, Oregon, on charges apparently arising from other acts involving the same fraudulent plan.

The actual value of Chisholm’s mineral rights, and the nature of his title to them, were major issues at Glick’s trial. The testimony of the Government’s expert, a geologist with the Department of Interior, indicated that the value of the claims was far below that shown on the financial statements. He stated that Chisholm faced insurmountable obstacles in any effort to mine the limestone or to obtain the fee simple title necessary for a proposed real estate development.

Glick testified that before and during the time he had prepared the financial statements, four appraisals had been made that substantially supported the values contained in the statements. Glick was unable to remember the authors or the details of the two earliest appraisals. The third report was prepared by a real estate appraiser, Smith, who was not a geologist and had an interest in the Chisholm business enterprises. Glick testified that he had not accepted the Smith appraisal at face value because Smith was not independent. Glick stated that Smith’s results had been verified by another independent real estate appraiser, Goldring, who had based his evaluation on facts and figures supplied by Smith. Although the Smith report was admitted into evidence, Glick was unable to produce the Goldring report.

Chisholm had obtained a fifth appraisal in 1978 in preparation for his Portland trial. This preliminary evaluation, from a geologist named Stickel, stated that one of the mineral claims contained sufficient limestone deposits to warrant consideration of commercial mining. This appraisal was admitted into evidence by stipulation of the parties, although Stickel himself did not testify.

The Government presented expert testimony that the financial statements prepared by Glick contained blatant violations of basic accounting principles. Glick himself had conceded that no lending institution would furnish a loan based on the Chisholm financial statements. Glick testified that he knew Chisholm was obtaining fees by presenting the financial statements to people, claiming that the documents could be used to back up loan applications. How[*642] ever, Glick testified that he believed the limestone deposits were of considerable value to Chisholm, and that he thought Chisholm’s loan packaging business was bona fide when he prepared the financial statements.

II.

THE INTENT INSTRUCTIONS

“Mail fraud is a specific intent crime. The government is required to prove beyond a reasonable doubt that the defendant intended to defraud.” United States v. Martin-Trigona, 684 F.2d 485, 492 (7th Cir.1982). The district court gave the following instruction on deliberate ignorance as part of its charge on the type of knowledge which satisfies the requisite fraudulent intent:

“However, the element of knowledge may be established by proof that a defendant deliberately closed his eyes to what otherwise would have been obvious to him. In other words, the requirement that the defendant has acted knowingly does not mean that the defendant needed to have positive knowledge. If the defendant failed to have positive knowledge only because he conscientiously avoided acquiring it, the requirement of knowledge is satisfied.”

Rec., vol. VIII, at 673. On appeal, Glick contends that this instruction is an erroneous formulation of the law because it permitted the jury to convict upon proof of a lesser degree of knowledge than that required by the statute.

In recommending the use of a deliberate ignorance instruction, this court has pointed out that “[wjhile negligence is not sufficient to charge a person with knowledge, one may not wilfully and intentionally remain ignorant of a fact, important and material to his conduct, and thereby escape punishment. The test is whether there was a conscious purpose to avoid enlightenment.” Griego v. United States, 298 F.2d 845, 849 (10th Cir.1962) (footnotes omitted). Thus, the type of instruction at issue here may be given when the evidence points to deliberate ignorance and conscious avoidance of actual knowledge. See United States v. Garzon, 688 F.2d 607, 609 (9th Cir.1982); United States v. Ciampaglia, 628 F.2d 632, 642-43 (1st Cir.), cert. denied, 449 U.S. 956, 101 S.Ct. 365, 66 L.Ed.2d 221, 449 U.S. 1038, 101 S.Ct. 618, 66 L.Ed.2d 501 (1980); United States v. Brien, 617 F.2d 299, 312 (1st Cir.), cert. denied, 446 U.S. 919, 100 S.Ct. 1854, 64 L.Ed.2d 273 (1980); United States v. Batencort, 592 F.2d 916, 918 (5th Cir.1979).

Glick argues that giving a deliberate ignorance instruction was inappropriate in light of the evidence presented at trial. This argument is apparently based on Glick’s assertion that the record does not contain sufficient evidence of his willful ignorance in the face of facts known to him that would have made obvious the existence of the fraudulent scheme.

In denying Glick’s motion for directed verdict, the trial judge determined that the instruction was proper because a reasonable juror could find that Glick had intentionally remained ignorant despite his subjective awareness of facts plainly indicating the fraudulent nature of Chisholm’s business. The court specifically noted evidence of Glick’s numerous blatant violations of accounting principles and auditing standards, his belief in 1975 that the mineral claim evaluations were unrealistic, his acknowledgment that no one would give a loan on the basis of the financial statements, his knowledge that fees were obtained for packaging loans which would likely not go through, and his knowledge of the nature of the corporate financial activities. This evidence is sufficient to enable a jury to find beyond a reasonable doubt that Chisholm’s loan packaging business was a fraudulent scheme from its inception, and that Glick either knew it or deliberately avoided acquiring positive knowledge. Accordingly, we conclude that an instruction on deliberate avoidance was appropriate. See Griego, 289 F.2d at 849.

Glick also argues that even if a deliberate ignorance instruction was warranted, the form of the instruction given in this case was inadequate because it failed to[*643] require the jury to find that “the defendant was subjectively aware of a high probability of the existence of the fact whose knowledge is imputed, and that knowledge of that fact may not be imputed if the defendant actually believed that such fact did not exist.” Brief of Appellant at 17. To insure that a defendant is only convicted if his ignorance is willful, rather than negligent, the preferable form of the instruction informs the jury, in addition to the charge given in this case, “(1) that the required knowledge is established if the accused is aware of a high probability of the existence of the fact in question, (2) unless he actually believes it does not exist.” United States v. Jewell, 532 F.2d 697, 704 n. 21 (9th Cir.) (en banc), cert. denied, 426 U.S. 951, 96 S.Ct. 3173, 49 L.Ed.2d 1188 (1976); see also United States v. Aulet, 618 F.2d 182,190-91 (2d Cir.1980). Glick urges that the court’s failure to add this language to its charge is grounds for reversal. We disagree.

In response to counsel’s general objection to the instruction, the district court repeatedly offered to modify the instruction if counsel wished to propose a language change. ^[3] Defense counsel responded that his objection was not to the language of the instruction, but to the propriety of such an instruction in any form. Because Glick failed to suggest to the trial court the language he now claims was erroneously omitted, we may reverse only if the omission constitutes plain error. Fed.R.Crim.P. 52(b).

The jury was instructed that Glick could not deliberately close his eyes to what would otherwise be obvious to him, that he could not be convicted for an act done because of mistake, accident, or innocent reason, and that he was innocent even if he prepared fraudulent financial statements if he did not intentionally and knowingly participate in the scheme or artifice to defraud. ^[4] Although inclusion of the omitted[*644] language would have been preferable, the omission in this case did not constitute plain error. See United States v. Cincotta, 689 F.2d 238, 243-44 (1st Cir.), cert. denied, ___ U.S. ___, 103 S.Ct. 347, 74 L.Ed.2d 387 (1982); United States v. Eaglin, 571 F.2d 1069, 1074-75 (9th Cir.1977), cert. denied, 435 U.S. 906, 98 S.Ct. 1453, 55 L.Ed.2d 497 (1978); Jewell, 532 F.2d at 704 n. 21.

III.

ADEQUACY OF COUNSEL

Glick claims he was denied effective assistance of counsel because his trial attorney ^[5] allegedly failed to conduct adequate pretrial preparation and was therefore unable to present an effective defense at trial. Glick points specifically to counsel’s failure both to investigate the existence and nature of the two earliest mineral appraisals and the Goldring appraisal, and to determine the possibility of obtaining favorable independent expert testimony from Stickel concerning the value of the limestone.

“The Sixth Amendment demands that defense counsel exercise the skill, judgment and diligence of a reasonably competent defense attorney.” Dyer v. Crisp, 613 F.2d 275, 278 (10th Cir.) (en banc), cert. denied, 445 U.S. 945, 100 S.Ct. 1342, 63 L.Ed.2d 779 (1980). In considering an allegation of incompetent counsel, the court must first determine whether the attorney’s performance fell below this standard. The court must then determine whether the inadequacy “has had or threatens some adverse effect upon the effectiveness of counsel’s representation or has produced some other prejudice to the defense.” United States v. Morrison, 449 U.S. 361, 365, 101 S.Ct. 665, 668, 66 L.Ed.2d 564 (1981). ^[6]

The proper standards for evaluating a claim of ineffective assistance of counsel based upon allegations of inadequate trial preparation were recently addressed in Washington v. Strickland, 693 F.2d 1243 (5th Cir.1982) (en banc), petition for cert. granted, ___ U.S. ___, 103 S.Ct. 2451, 77 L.Ed.2d 1332. Effective counsel must “conduct a reasonable amount of pretrial investigation,” id. at 1251, which “will necessarily depend upon a variety of factors including the number of issues in the case, the relative complexity of those issues, the strength of the government’s case, and the overall strategy of trial counsel.” Id.

“[A]n attorney who makes a strategic choice to channel his investigation into fewer than all plausible lines of defense is effective so long as the assumptions upon which he bases his strategy are reasonable and his choices on the basis of those assumptions are reasonable.” Id. at 1256. “Courts presume, in accordance with the general presumption of attorney competence, that counsel’s actions are strategic.” Id. at 1257; see DuPree v. United States, 606 F.2d 829, 830 (8th Cir.1979) (per curiam), ce rt. denied, 445 U.S. 919, 100 S.Ct. 1284, 63 L.Ed.2d 605 (1980). An attorney’s decision not to interview witnesses and to rely on other sources of information, if made in the exercise of professional judgment, is not ineffective counsel. Plant v. Wyrick, 636 F.2d 188, 189-90 (8th Cir.1980). “Whether to call a particular witness is a tactical decision and, thus, a ‘matter of discretion’ for trial counsel.” United States v. Miller, 643 F.2d 713, 714 (10th Cir.1981). Counsel is not inadequate in failing to call a witness whose testimony would only have been cumulative in nature. Id.

[*645] In applying the above standards to the allegations before us, we note the lack of any objective showing that the missing appraisals were available, credible, or favorable to Glick. We have only Glick’s self-serving statements as to the existence and contents of the two early appraisals and the Goldring report. Moreover, we will presume in the absence of any evidence to the contrary that counsel’s decision not to produce the documents, even if they were available, was a matter of trial strategy.

We also conclude that defense counsel’s decision not to call Stickel as a witness was a question of trial tactics. The Stickel report, which tended to support Glick’s assertion that the limestone was valuable, was admitted into evidence. Counsel stated to the court that he was unsure of Stickel’s value as a witness for Glick because Chisholm still owed Stickel about $40,000. Counsel had read the transcript of Stickel’s testimony on behalf of Chisholm in the Portland trial, and was thus in a position to evaluate the benefits and drawbacks of calling Stick-el to testify for Glick. Under these circumstances, the determination not to call Stick-el for the defense was a reasonable tactical decision. See Washington v. Strickland, 693 F.2d at 1255. We have considered Glick’s other allegations of inadequacy and find them unpersuasive.

Finally, we note that Glick’s trial counsel is a criminal law specialist, a former prosecutor, and a member of the California Council of Criminal Justice. He had been hired by the Justice Department to represent United States Attorneys charged with perjury.

After reviewing the record, we agree with the Government that counsel’s trial strategy was apparently to convince the jury that the Government had hidden witnesses and documents helpful to the defense. Moreover, the absence of the documents and testimony made it possible for counsel to imply to the jury that the evidence would have been favorable to Glick. We conclude on this record that Glick received effective assistance of counsel.

AFFIRMED.