OPINION OF THE COURT
GIBBONS, Circuit Judge:
In these consolidated appeals Richard P. Herman (No. 78-1252) and James J. McCann (No. 78-1282), former state court magistrates in Allegheny County, Pennsylvania, appeal from judgments of sentence following their conviction for violating the Racketeer Influenced and Corrupt Organizations Act (RICO).1 We affirm Herman’s conviction but reverse and remand for a new trial in McCann’s case.
The first count of the indictment charged Herman, McCann and others with conspiring to accept bribes offered by a bail bonding firm know as the Levitt Agency for the purpose of affecting their official behavior in fixing bail in criminal cases, in violation of 18 U.S.C. § 1962(d). In the second count, each man was charged with the substantive offense proscribed by § 1962(c) of associating with the Levitt Agency, an enterprise in commerce, and conducting its affairs through a pattern of racketeering activity. Before trial the defendants moved to dismiss the indictment and to suppress certain evidence; The district court granted these motions, the government appealed, and this court reversed.2 When on remand the indictment was moved for trial Herman and McCann were severed from the remaining defendants because of ill health.3 They were tried together with two constables, Zanello and Phillips, and found guilty.
The government’s chief witness was Stephen C. Levitt, who had pled guilty to a violation of 18 U.S.C. § 1962(d). Levitt testified that from February of 1970 through May of 1975 he operated a bail bond agency in Pittsburgh, Pennsylvania, writing surety bonds for persons charged with crimes throughout Western Pennsylvania. The principal and qualified surety for the agency was Stuyvesant Insurance Company, to whom Levitt was required to pay 2% of the face amount of each valid bond issued by the agency. Early in 1970 he made an arrangement with certain magistrates in Allegheny County to pay a kickback of 50% of the surety bond premium to magistrates who referred bail bond business to his newly established agency. When a defendant was referred to him by one of these magistrates, Levitt would usually post an invalid bond with the court. In some cases, he would post a surety bond without including the power of attorney required to bind Stuyvesant as surety; in others, he would post a worthless property bond. Both devices avoided the necessity of making any premium payment to Stuyvesant. If the case was dismissed at the preliminary hearing he would split the gross premium with the magistrate. If the case was held for court he would deduct the cost of obtaining a valid power of attorney, and split the remainder of the premium. Often after a valid bond had been posted the magistrate would surreptitiously reduce the amount of the bond with no premium refund to the defendant, thereby lowering the required payment to the surety and increasing the sum which was split with the magistrate. Relying upon the Levitt Agency files,4 which listed individual bond transactions by date and name of defendant, Levitt illustrated how he had calculated the specific sums paid to Herman and McCann on account of each bond. He further testified that on each such occasion he' had placed the money in an envelope with the appropriate magistrate’s name on it, and had either personally delivered the envelope to the magistrate or one of his employees, or directed that it be so delivered.
[1195]*1195Victor Kozlowski, a former bailbondsman at the Levitt Agency, testified under a grant of immunity. He corroborated Levitt’s testimony, and stated that at Levitt’s direction he personally had delivered kickbacks to Herman and McCann for cases in which he had written the bail bonds at their office. Mary Hupert, formerly a secretary at the Agency, also testified under an immunity grant. She stated that she had observed, and later prepared, envelopes directed to Herman and McCann and that she had received phone calls from both magistrates and their staffs referring bail bond clients to the Levitt Agency. She further testified that she recalled an occasion on which Magistrate Herman’s son had picked up a payment envelope at the Levitt Agency-
Eugene Benedik, a former constable in McCann’s office, testified that McCann had personally instructed him to refer arrested persons in need of a bond to the Levitt Agency. He also stated that he had picked up kickbacks from the Levitt Agency and had divided those payments with McCann and with his co-constable, one Wagner. Special Agent Marinaro of the FBI testified that during a lengthy interview with the FBI on February 25, 1976, Herman had admitted that he had sent his son to pick up an envelope containing several hundred dollars from the Levitt Agency as kickback payments on bonds written in cases heard before him.
McCANN’S APPEAL
During its case in chief the government attempted to introduce the testimony of Jacob Winner, who operated a bail bond agency in Pittsburgh known as the American Bonding Company, to the effect that between 1970 and 1972 he paid to Herman and McCann 50% of his premiums on all bonds which he posted in cases where they had fixed bail. The trial court ruled that the testimony was inadmissible. After the government rested its case McCann testified in his own defense. He denied having taken money or anything of value from the Levitt Agency. Neither in his direct testimony or on cross examination did he mention Winner or the American Bonding Company. He also presented the testimony of three constables who worked in his office, his secretary, and a local police chief, all of whom stated that they had no knowledge of a kickback or referral arrangement with McCann’s office. Each of these witnesses testified only to his or her own lack of knowledge of any payoffs or referrals, not that no payoff from a bail bond agency ever occurred.5 Since McCann’s defense counsel was well aware of Winner’s availability to the prosecution he quite carefully avoided any testimony which can fairly be construed as a denial of wrongdoing with respect to any bail bond agency other than the Levitt Agency. The defense did, however, present the testimony of seventeen character witnesses. Many of these testified, without objection, to specific acts of benevolence by McCann.
In rebuttal the government sought once again to introduce the Winner testimony.6 McCann’s counsel objected. He pointed [1196]*1196out, and the court agreed,7 that McCann’s denial of receipt of kickbacks was limited solely to the Levitt Agency. The court, however, ruled that the Winner testimony was admissible solely as rebuttal to the character evidence offered by McCann.8 Winner then testified substantially as set forth in the government’s offer of proof. In its charge the trial court restated the limited purpose for which the Winner testimony had been admitted, admonishing the jury that it could not be considered for any purpose except to rebut the character testimony that was offered by McCann.9 McCann contends that the court erred in admitting the testimony even for that purpose.
Neither in its ruling nor in the jury charge did the court make any reference to the federal rule of evidence relied upon for admission of the Winner testimony. Since McCann had testified, it is possible that the court had in mind rule 608, which governs the admission of evidence concerning the character and conduct of witnesses. If so, admission of the Winner testimony was error, for rule 608(b) expressly provides that “[sjpecific instances of the conduct of a witness, for the purpose of attacking or supporting his credibility, other than conviction of crime as provided in rule 609, may not be proved by extrinsic evidence.” E. g., United States v. Edwards, 549 F.2d 362, 367-68 (5th Cir.), cert. denied, 434 U.S. 828, 98 S.Ct. 107, 54 L.Ed.2d 87 (1977); United States v. Cluck, 544 F.2d 195, 196 (5th Cir. 1976); United States v. Blackshire, 538 F.2d 569 (4th Cir.), cert. denied, 429 U.S. 840, 97 S.Ct. 113, 50 L.Ed.2d 108 (1976).
The government urges that a judge-made exception to rule 608(b) permits contradiction by specific uncharged acts of misconduct when a defendant’s own testimony places his conduct or character in a “false light.” For this proposition it cites United States v. Batts, 558 F.2d 513 (9th Cir. 1977), modified on rehearing, 573 F.2d 599 (1978). In Batts, the defendant was charged with smuggling hashish. When arrested he was wearing a “coke spoon.” During questioning about the spoon during cross examination, he denied all knowledge of cocaine use. The court of appeals originally held that this general denial justified admission under rule 608(b) of rebuttal testimony that [1197]*1197the defendant had recently sold a large quantity of cocaine to an undercover agent. Judge Kennedy’s persuasive dissent in Batts, 558 F.2d at 519, to the effect that the majority misconstrued the intention of the draftsmen of rule 608(b), would make us hesitate to accept the “false light” rationale even if the record supported its application. See Weinstein’s Evidence 1608[5] at 608-28 (1977); Note, 9 Rut.-Cam. J. L. 375 (1977). Moreover, we cannot help but think that the Batts court’s subsequent modification of the opinion to eliminate all reliance upon rule 608(b) as a ground of admissibility at least implicitly acknowledges the force of Judge Kennedy’s view of the matter. But Batts is distinguishable from this case. Here, as the trial judge acknowledged, McCann’s testimony was limited to the Levitt Agency transactions. He made no assertion of his general probity and the Winner testimony rebutted no false light created by him. Moreover, none of the witnesses stated more than their lack of knowledge of the receipt of kickbacks or the making of referrals. Thus the Batts rationale would not on this record support admissibility of Winner’s testimony.
Rule 405 governs use of specific evidence of conduct to prove good or bad character. It restricts such evidence to expressions of reputation or of opinion. It does not permit the affirmative use of specific instances of conduct except where “character or a trait of character of a person is an essential element of a charge, claim or defense.” Fed.R.Evid. 405(b). That ground of admissibility is unavailable in this prosecution. The only other use of specific instances of conduct authorized by the rule is in cross examination of character witnesses. Fed.R.Evid. 405(a). No such cross examination took place. If it had, and a witness had denied knowledge of a specific instance of conduct called to his attention, an argument might be made that the Winner testimony was admissible to contradict the witness’s denial. But on this record that argument was foreclosed.
. Nevertheless the government relies on dictum in United States v. Chrzanowski, 502 F.2d 573, 576 (3d Cir. 1974), which states that prior crimes testimony is properly admissible “to rebut the testimony of the character witnesses by showing that the defendants had committed similar acts.” But as Judge Hunter’s concurring opinion makes clear, the character witnesses in Chrzanowski went beyond statements of reputation or opinion, and testified to specific events tending to show a legitimate modus operandi. 502 F.2d at 579. Thus the propriety of the use of specific events evidence in the Chrzanowski case turns on the defense’s decision there to place modus op-erandi in issue in its own direct case. See Government of the Virgin Islands v. Toto, 529 F.2d 278, 283 (3d Cir. 1976). If the Chrzanowski court intended that its dictum be given a broader reading, the text of rule 405 makes it clear that such a reading did not survive the subsequent adoption of the Federal Rules of Evidence.
The government also urges that because the character witnesses testified, improperly but without objection, to specific acts of beneficence on McCann’s part, the defense opened the door to other crimes evidence. We fail to see why the government’s failure to object to character testimony going beyond that permitted by rule 405(a) should be a ground for the admissibility of other crimes evidence otherwise inadmissible. The same contention was made and rejected in United States v. Benedetto, 571 F.2d 1246, 1250 (2d Cir. 1978).
Finally, the government argues that even if the court erred in admitting the Winner testimony as rebuttal of character testimony the error was harmless, because the court had erred in refusing to admit the testimony under rule 404(b) when it was offered as a part of the prosecution’s direct case. Winner’s testimony, it is said, was probative of McCann’s participation in a common scheme or plan, and of the modus operandi of that plan. However the indictment charges a common plan with the Levitt Agency only. It is true that the modus operandi of the Winner offenses was in some respects similar to that of the Levitt offenses. But the evidence must still be [1198]*1198evaluated, under rule 403, for undue prejudice, confusion of issues, and needless presentation of cumulative evidence. United States v. Long, 574 F.2d 761 (3d Cir. 1978); United States v. Cook, 538 F.2d 1000 (3d Cir. 1976). While in most instances we would defer to the district judge’s sound discretion concerning a rule 403 issue, see United States v. Long, 574 F.2d at 767, where, as here, the evidence was admitted under a different theory from that urged on appeal, and defense counsel strongly objected to its prejudicial effect, a more searching inquiry is required.
In determining the probative value of evidence under rule 403 we must consider not only the extent to which it tends to demonstrate the proposition which it has been admitted to prove, United States v. Stirone, 262 F.2d 571, 576 (3d Cir. 1959), rev’d on other grounds, 361 U.S. 212, 80 S.Ct. 270, 4 L.Ed.2d 252 (1960), but also the extent to which that proposition was directly at issue in the case. United States v. Cook, supra, 538 F.2d at 1004. In this case, the fact that the means used to commit the charged and uncharged crimes were somewhat similar had little probative weight, particularly since the jury had already been informed by Levitt that the 50% payment scheme, far from being unique, had been used with many other magistrates in Allegheny County. In view of that testimony, it cannot seriously be argued that the modus operandi described in Winner’s testimony was so unusual and distinctive that its similarity to the modus operandi described by Levitt by itself justified an inference that McCann had participated in both transactions. Moreover, modus operandi was at best a collateral issue in the case. What was centrally in issue was whether McCann was the kind of person who would take a bribe. The Winner testimony, if believed, tended to show that McCann was just such a person. Its effect was thus highly prejudicial to his defense. Since the probative value of the evidence as modus operandi testimony was clearly outweighed by its prejudicial effect on McCann’s character defense, we hold that it was proper to exclude the evidence when it was offered in the government’s direct case, and that its admission on an impermissible theory in rebuttal was not harmless error.
Because the court erred in admitting evidence of other crimes committed by McCann his sentence must be vacated and the case remanded for a new trial.
Defendant McCann also contends:
(1) that the government’s proof established multiple rather than a single conspiracy;
(2) that a violation of 18 U.S.C. § 1962(c) and (d) occurs upon the making of an agreement and is not a continuing offense, and thus that the offense took place prior to the effective date of the statute;
(3) that the government failed to prove the elements of a § 1962 offense;
(4) that his severance motions should have been granted;
(5) that § 1962(c) is unconstitutionally vague;
(6) that the court’s charge impermissi-bly broadened the charge made by the grand jury; and
(7) that the court should reconsider the rulings it made in a prior appeal, United States v. Forsythe, 560 F.2d 1127 (3d Cir. 1977).
On the record before us we find no merit in these contentions. Thus we reject his contention that the indictment should be dismissed rather than remanded for a new trial.
HERMAN’S APPEAL
The Winner testimony was not admitted against Magistrate Herman, and in no way prejudiced him. He urges two grounds for the grant of a new trial which on the record before us we find to be without merit:
(1) that the government offered no evidence tending to prove the predicate offense of bribery under Pennsylvania law, and thus did not prove a violation of 18 U.S.C. § 1962(c) and (d);
[1199]*1199(2) that the court’s charge impermissi-bly broadened the charge made by the grand jury.
These grounds require no discussion.
Herman also contends, however, that he was denied a fair trial because he was deprived of his sixth amendment right to have compulsory process for obtaining witnesses in his favor. At trial, Herman put on four witnesses. Three former constables in his office — James Regrut, Robert Williams, and William McHugh — testified that they had never split with Magistrate Herman any funds received from Levitt. Since, however, Regrut denied ever having received any money from Levitt, Williams stated that he had received money only for picking up bail jumpers, and McHugh was not required to testify as to the reason that he received money from Levitt, the force of this testimony was muted. Herman’s secretary, Josephine Howe, testified that she had never made any referrals to bail bond agencies; that, to her knowledge, it was not Magistrate Herman’s policy to make such referrals; and that, to her knowledge, Magistrate Herman had never taken any bribes or kickbacks in the performance of his duties.
In addition, Herman proposed to call as defense witnesses McHugh and three other constables who had on occasion done work out of Herman’s office. Relying upon prior admissions made by the constables to the FBI and the grand jury, he represented to the court that their testimony would establish that some payments from the Levitt Agency with respect to bail bond business originating out of Herman’s office went to one or more of the constables, who split the money among themselves without passing any along to him. The constables were subpoenaed. At a hearing out of the presence of the jury, however, McHugh invoked the privilege against self incrimination when asked about the disposition of funds received from Levitt. Counsel for the other three constables also- informed the court that if asked about receiving or disposing of payments from the Levitt Agency each would assert the privilege against self incrimination and would refuse to testify.
A hearing was held on that assertion of the privilege at which it was established that each constable had been indicted for his alleged participation in the Levitt Agency bail bond conspiracy. Prior to the start of Herman’s trial the charges against each of them had been dismissed without prejudice. The statute of limitations had not, however, run on the offenses, and the constables had not been granted immunity. The court quite properly sustained the constables’ assertion of the privilege against self incrimination. Herman then moved that the government and the court grant them immunity, so that their testimony could be compelled, or in the alternative that the indictment should be dismissed. No suggestion was made that either the court or the government acted improperly in order to cause the constables to assert the privilege against self incrimination.
A. The Sixth Amendment Claim
In support of his claim that the indictment should be dismissed because potential defense witnesses were not granted use immunity Herman relies on United States v. Morrison, 535 F.2d 223 (3d Cir. 1976). That reliance is misplaced. In Morrison the government’s attorney threatened and intimidated a defense witness who, pri- or to the government’s activity, had indicated her intention not to assert the privilege against self incrimination. The witness then invoked the privilege and refused to testify. We held that the sixth amendment and the Due Process Clause guarantee to a defendant the right to subpoena a witness, and to have that witness available as he finds him. See Washington v. Texas, 388 U.S. 14, 19, 87 S.Ct. 1920, 18 L.Ed.2d 1019 (1967). The government’s threats and intimidation had violated that right by depriving the defendant of that witness’s testimony. See Webb v. Texas, 409 U.S. 95, 93 S.Ct. 351, 34 L.Ed.2d 330 (1972). This violation warranted the dismissal of the indictment. We then turned to the separate question whether, because of the availability of use immunity under 18 U.S.C. [1200]*1200§§ 6002-6003, the government could cure the sixth amendment violation which it had committed. We held that it could:
At the new trial, in the event that the defendant calls Sally Bell as a witness, if she invokes her Fifth Amendment right not to testify, a judgment of acquittal shall be entered unless the Government, pursuant to 18 U.S.C. §§ 6002, 6003, requests use immunity for her testimony.
535 F.2d at 229.
Here there has been neither threat nor intimidation, beyond that implicit in the existence of a penal statute and the availability of a new indictment. Herman would have us read the Morrison case for the proposition that defendants have a general sixth amendment right to demand that witnesses of their choice be immunized or that their indictments be dismissed. It does not so hold. The violation in Morrison was the government’s threats and intimidation of the witness. The use of a grant of immunity from the executive branch, a creature solely of statute, and intended solely to benefit the government, was only a cure for that violation. In United States v. Rocco, 587 F.2d 144 (3d Cir. 1978), we recently rejected a contention substantially identical to the defendant’s broader proposition. Accord, United States v. Niederberger, 580 F.2d 63 (3d Cir. 1978); United States v. Beasley, 550 F.2d 261, 268 (5th Cir.), cert. denied, 434 U.S. 938, 98 S.Ct. 427, 54 L.Ed.2d 297 (1977); United States v. Bautista, 509 F.2d 675 (9th Cir.), cert. denied, 421 U.S. 976, 95 S.Ct. 1976, 44 L.Ed.2d 467 (1975) ; United States v. Berrigan, 482 F.2d 171, 190 (3d Cir. 1973); United States v. Smith, 436 F.2d 787, 790 (5th Cir.), cert. denied, 402 U.S. 976, 91 S.Ct. 1680, 29 L.Ed.2d 142 (1971); Earl v. United States, 124 U.S.App.D.C. 77, 361 F.2d 531 (1966), cert. denied, 388 U.S. 921, 87 S.Ct. 2121, 18 L.Ed.2d 1370 (1967); People v. Sapia, 41 N.Y.2d 160, 391 N.Y.S.2d 93, 359 N.E.2d 688 (1976) . But see, Westen, The Compulsory Process Clause, 73 Mich.L.Rev. 71, 166-170 (1974); Note, The Sixth Amendment Right to Have Use Immunity Granted to Defense Witnesses, 91 Harv.L.Rev. 1266 (1978).
B. The Statutory Claim
The dissent, however, constructs an ingenious statutory argument for a different result. Judge Garth, relying upon the judicial review provisions of the Administrative Procedure Act, reasons that the United States Attorney is an “agency” for purposes of the judicial review provisions of that act. He then concludes that, in the absence of an express prohibition in the Organized Crime Control Act of 1970 of judicial review of decisions to withhold immunity, such review is appropriate to determine whether the prosecutor’s decision is in the “public interest.” He further argues that the defendant has standing to seek such review.
This argument has several flaws. Of these, perhaps the most obvious is the fact that district court review of the immunity decision to determine whether it is in the “public interest” raises grave issues of separation of powers. Under the statute, the “agency” which makes the immunity decision is not merely the United States Attorney, but also the Department of Justice. Section 201(a) of the Act, 18 U.S.C. § 6003, provides that the United States Attorney may request a grant of immunity only with the approval of the Attorney General, the Deputy Attorney General, or a designated Assistant Attorney General. Thus any judicial review of the immunity decision must necessarily trench seriously upon the authority of the executive branch. Moreover, “public interest” review would necessarily, require the court to weigh, if only in limited circumstances, the considerations that are traditionally associated with the decision to prosecute. Both the degree of intrusion and the nature of the proposed decision raise doubts of constitutional magnitude as to whether it is appropriate for a court to take on such a task.
These doubts are not new — in fact they were raised after the passage of the Immunity Act of 1954.10 That statute, one of the predecessors of the current immunity stat[1201]*1201utes, also required as a precondition for the order of immunity an application from the United States Attorney certifying that in his judgment the witness’s testimony was necessary to the “public interest.” It further provided that “upon order of the court” the witness could be required to testify despite his fifth amendment privilege. The statute, however, did not clearly specify the nature of the court’s responsibility for review when presented with such an order. In Ullman v. United States, 350 U.S. 422, 76 S.Ct. 497, 100 L.Ed. 511 (1956), a reluctant witness challenged the constitutionality of the 1954 Act on the ground, inter alia, that by providing for district court review of the United States Attorney’s determination that an immunity grant was in the public interest, the statute required the court to perform a non-judicial function. In the district court, Judge Wein-feld found it unnecessary to pass upon the question “whether ... a power in the court to approve a grant of immunity offends constitutional limitations,” In re Ullman, 128 F.Supp. 617, 624 (S.D.N.Y. 1955), because the statute could fairly be construed as requiring the district court to do no more than determine that the United States Attorney and the Justice Department were in fact in agreement that the grant of immunity was in the “public interest,” and because such a construction was required by the policy of avoiding unnecessary decision of constitutional questions. Id. at 624-28. Under this construction the role of the district court was simply to determine whether the formal prerequisites for an immunity grant had been complied with before granting the order.
On appeal, the Supreme Court strongly endorsed Judge Weinfeld’s reasoning, holding that:
[sjince the court’s duty under § (c) [of the Act] is only to ascertain whether the statutory requirements are complied with by the grand jury, the United States Attorney, and the Attorney General, we have no difficulty in concluding that the district court is confined within the scope of “judicial power.” Interstate Commerce Commission v. Brimson, 154 U.S. 447, 14 S.Ct. 1125, 38 L.Ed. 1047.
350 U.S. at 434, 76 S.Ct. at 504.
The legislative history of section 6004 of the current use immunity statute makes it clear that Congress knew of the construction adopted in Ullman and approved of it. On the subject of judicial review, the House Report stated that “[t]he court’s role in granting the order is merely to find the facts on which the order is predicated.” H.R.Rep.No.91-1549, 91st Cong., 2d Sess., reprinted in [1970] U.S.Cong. & Admin. News, pp. 4007, 4018. In conjunction with this direction, the Report then cited with approval In re Bart, 113 U.S.App.D.C. 54, 58, 304 F.2d 631 (1962), where Judge Wright, relying on Ullman, had held that:
[the “public interest” language of the immunity statute] does not address itself to the Judiciary. The application should say, explicitly, that such is the opinion of the United States Attorney and show the Attorney General’s concurrence, but, having stated their conclusion, the government’s attorneys need not justify it. The court cannot review their judgment in this regard.
Id. at 58, 304 F.2d at 635. (emphasis added) (footnote omitted).
There is thus overwhelming judicial and legislative authority for the proposition that review on the merits of a federal prosecutor’s decision to grant immunity is barred by statute. The dissent, however, concludes that a contrary rule must prevail in the case of a decision not to grant immunity. We cannot agree. The same separation of powers concerns that compelled Ullman’s construction of the statute to deny any possibility that a court might bar the prosecutor’s ' application for a grant of immunity apply with equal force to a court order requiring such a grant. It may be true that the “interests” of the .judicial branch are more implicated by a denial of immunity than by a grant thereof. But surely the gravamen of the Ullman holding is that judicial interests of nonconstitutional stature are insufficient to permit intervention in the prosecutor’s immunization decision.
[1202]*1202Even if constitutional separation of powers concerns and the statutory construction founded upon them did not wholly bar the notion of review advanced in the dissent, the purpose and structure of the statute would persuade us that Congress did not intend to provide for such review at the behest of a criminal defendant. The Administrative Procedure Act grants standing to seek review only to those persons “suffering legal wrong because of agency action, or adversely affected or aggrieved by agency action within the meaning of a relevant statute.” 5 U.S.C. § 702 (1977). It is well settled that to meet this requirement the person seeking review must show not only injury in fact, but also that “the interest sought to be protected by the complainant is arguably within the zone of interests to be protected or regulated by the statute or constitutional guarantee in question.” E. g., Association of Data Processing Service Organizations, Inc. v. Camp, 397 U.S. 150, 151-53, 90 S.Ct. 827, 25 L.Ed.2d 184; Barlow v. Collins, 397 U.S. 159, 90 S.Ct. 832, 25 L.Ed.2d 192 (1970). The dissent eschews reliance upon any constitutional provision. The defendant’s protected interest must therefore derive from the immunity statute itself, as enacted in the Organized Crime Control Act of 1970. Yet nothing on the face of that statute or in its legislative history suggests any congressional intention to confer benefits of any kind upon the defendant. The express terms of the statute of course nowhere indicate that review is authorized. And insofar as the working of the statutory mechanism casts any light upon the purposes of Congress it indicates that improving the lot of criminal defendants was not among them. The only occasion for even the limited review expressly contemplated in the legislative history is when the prosecutor brings the issue of immunity before the court to request its assistance in coercing the witness. There can certainly be no fair implication from this restrictive provision for review that the statute also contemplates that the district court would in addition have the power to review, in a much more sweeping fashion, a decision of the prosecutor never presented to it at all.
The legislative history of the immunity statutes also shows no sign of a purpose to benefit defendants. The narrow purpose of the use immunity provisions was twofold: to eliminate those federal immunity statutes that required conferral of transactional rather than use immunity and to reduce the number and complexity of immunity statutes. The shift to use immunity was intended to take advantage of the more favorable view of use immunity expressed by the Supreme Court in Murphy v. Waterfront Commission, 378 U.S. 52, 84 S.Ct. 1594, 12 L.Ed.2d 678 (1964).11 See Kastigar v. United States, 406 U.S. 441, 455-59, 92 S.Ct. 1653, 32 L.Ed.2d 212 (1972). The clear intent of the shift to use immunity was to make it less costly for the United States Attorney to grant immunity, by allowing for fuller prosecution of both the defendant and the immunized witness. In broader perspective, it is apparent that the immunity statute was part of a massive program of legislation whose central purpose, as its opponents recognized,12 was to strengthen the hand of the prosecution and to weaken that of the criminal defendant, in many cases to the full extent permitted by the protections of the Bill of Rights.
The total absence of any indication that Congress intended to create a protected interest in the defendant is particularly striking in view of the traditional assumptions on which the adversary system is founded. Surely Congress must have legislated with full knowledge that federal prosecutors have always had the ability to protect any defendant as to whom exculpatory material becomes available simply by dismissing the prosecution against him; that a defendant always retains the right to request a non-suit where at the close of the prosecution’s case the evidence for conviction is insuffi[1203]*1203cient as a matter of law; and that the jury must be convinced beyond a reasonable doubt before it can convict. Prior to the passage of the immunity statutes, these safeguards were, we presume, generally considered adequate to protect against the risk of unjustified conviction even when a critical witness pleaded the Fifth Amendment. If Congress felt otherwise and in fact intended to broaden the historical remedies available to defendants, it is inconceivable to us that it would have made this radical change in a statute which by its express terms leaves the power to request such relief solely in the hands of the prosecutor and which contains no hint in the statute or in the legislative history that such was its purpose.
For all of the foregoing reasons, we conclude that the federal immunity statute cannot legitimately be construed to authorize judicial review of the prosecutorial decision not to immunize a defense witness. Nor do we think that this construction of the statute raises any constitutional difficulties. We note, first, that the statute cannot be attacked on the ground that it unconstitutionally discriminates against defendants by making immunity available only in the discretion of the prosecution. Due process has never yet been held to require that the defendant be permitted to marshal precisely the same investigative and legal resources as the prosecution, and Congress could legitimately have concluded that the defendant should not be empowered by statute to impose upon the prosecution the burden of an unwanted grant of immunity. In re Kilgo, 484 F.2d 1215, 1222 (4th Cir. 1973). The cases decided under the Compulsory Process Clause do not suggest or require a different result. They hold no more than that the government may not act directly to prevent an otherwise willing and competent witness from testifying on the defendant’s behalf. See Webb v. Texas, 409 U.S. 95, 93 S.Ct. 351, 34 L.Ed.2d 330 (1972); Washington v. Texas, 388 U.S. 14, 87 S.Ct. 1920, 18 L.Ed.2d 1019 (1967). They are therefore consistent with our analysis of the compulsory process right in Morrison. For the same reason, the Confrontation Clause decisions of the Supreme Court are also inapposite. They hold only that when the prosecution has made a decision to present evidence in its own case against the defendant, due process requires that such evidence be subjected wherever possible to the tests of reliability provided for by the sixth amendment. E. g., Davis v. Alaska, 415 U.S. 308, 94 S.Ct. 1105, 39 L.Ed.2d 347 (1974); Pointer v. Texas, 380 U.S. 400, 85 S.Ct. 1065, 13 L.Ed.2d 923 (1965). None of them involves judicial interference with the executive’s discretionary decision whether to prosecute or to grant use immunity in exchange for testimony helpful to the prosecution.
C. The Due Process Claim
We are aware that several courts have suggested that in a case where the government relies on the testimony of witnesses who have received a grant of immunity, it may have an obligation, as a matter of fundamental fairness, to grant use immunity for defense witnesses as well. E. g., United States v. Alessio, 528 F.2d 1079, 1081-82 (9th Cir.), cert. denied, 426 U.S. 948, 96 S.Ct. 3167, 49 L.Ed.2d 1184 (1976); United States v. Bautista, supra, 509 F.2d at 677; Earl v. United States, supra, 361 F.2d 534 n. 1. Cf. In re Kilgo, supra. In this case both Victor Kozlowski and Mary Hupert testified against Herman under grants of immunity, and that question is therefore squarely before us. We adhere, however, to our conclusion that a grant of immunity was not required. The issue posed by the cited cases, we think, is not whether the legislative decision to leave the immunization decision in the hands of the prosecution was constitutionally permissible, but rather whether in the case before the court the prosecution has exercised that discretion in a manner that violates the Due Process Clause. In view of our governmental system’s strong tradition of deference to prosecutorial discretion, see United States v. Nixon, 418 U.S. 683, 693, 94 S.Ct. 3090, 41 L.Ed.2d 1039 (1974); Linda R. S. v. Richard D., 410 U.S. 614, 619, 93 S.Ct. 1146, 35 L.Ed.2d 536 (1973), and of the necessary [1204]*1204tendency of the executive branch to exercise that discretion in ways that make it more likely that defendants will be convicted, we think that the evidentiary showing required to justify reversal on that ground must be a substantial one. The defendant must be prepared to show that the government’s decisions were made with the deliberate intention of distorting the judicial fact finding process. Where such a showing is made, the court has inherent remedial power to require that the distortion be redressed by requiring a grant of use immunity to defense witnesses as an alternative to dismissal. United States v. Morrison, supra. No such finding, however, is possible in this case. So far as it appears, the decision to immunize Kozlowski and Hupert was unrelated to the decision first to prosecute, and later to drop the prosecution of the constables.
But while we think that the court has no power to order a remedial grant of statutory immunity to a defense witness absent a showing of unconstitutional abuse, a case might be made that the court has inherent authority to effectuate the defendant’s compulsory process right by conferring a judicially fashioned immunity upon a witness whose testimony is essential to an effective defense. The Supreme Court has authorized such grants in suppression hearings where the defendant’s testimony is necessary in order to determine whether a violation of his fourth amendment rights has occurred. Simmons v. United States, 390 U.S. 377, 88 S.Ct. 967, 19 L.Ed.2d 1247 (1968). This court has applied the rationale of Simmons where necessary to vindicate both a double jeopardy claim, United States v. Inmon, 568 F.2d 326 (3d Cir. 1977), and an assertion of privilege under the Speech or Debate Clause. In re Grand Jury Investigation, 587 F.2d 589, (3d Cir. 1978). It would seem that a case in which clearly exculpatory testimony would be excluded because of a witness’s assertion of the fifth amendment privilege would present an even more compelling justification for such a grant than that accepted in Simmons itself. Moreover, we find hints of a due process right to have clearly exculpatory evidence presented to the jury, at least when there is no strong countervailing systemic interest that justifies its exclusion, in Chambers v. Mississippi, 410 U.S. 284, 93 S.Ct. 1038, 35 L.Ed.2d 297 (1973).13
No case has been called to our attention where judicially fashioned use immunity has been granted to a witness, but analytically it is not immediately apparent why the power recognized in Simmons coupled with the constitutional right suggested in Chambers would not provide the basis for a grant of immunity in the proper circumstances. The existence vel non of such immunity power, and the standards which should govern its invocation and exercise, raise a host of difficult issues. It may be, for example, that such grants of immunity would on some occasions unduly interfere with important interests of the prosecution. Because the issue of inherent judicial power to grant use immunity was not raised in the district court, and the parties have not discussed it in the briefs or argument before us, we are reluctant to address it here. Moreover, Niederberger and Berrigan may well be regarded as at least sub silentio rejections of this rationale as well. If such inherent power is to be recognized and standards formulated for its exercise, that task should be performed in a case where the [1205]*1205issue was presented by the defendant, and perhaps by the court sitting in banc.
The judgment of sentence in No. 78-1282 will be vacated and the case remanded for a new trial of Magistrate McCann. The judgment in Magistrate Herman’s case, No. 78-1252, will be affirmed.