Dеfendants Anthony Tiano and Nicholas Lord appeal their criminal convictions on twelve counts of wire fraud, in violation of 18 U.S.C. § 1343 (1982). 1 Defendants were *1029 convicted, after a jury trial, for their involvement in a fraudulent telеmarketing scheme. The district court sentenced both defendants, pursuant to the United States Sentencing Guidelines, to twelve months’ incarceration.
On appeal, both defendants assert the following arguments: 1) the evidence was insufficient to convict them of the crimes charged; 2) the trial court erred by admitting evidence of the truthful character of three government witnesses; and 3) the triаl court denied defendants equal protection of the laws by refusing to credit their sentences for time spent in a halfway house as a condition of their release on bond. Defendant Lоrd asserts a fourth argument: the trial court erred in determining defendant Lord was not entitled to a two-level downward adjustment, under the sentencing guidelines, for being a minor participant in the fraudulent scheme.
In order to obtain a conviction for wire fraud under 18 U.S.C. § 1343, the government must establish 1) an interstate transmission by means of wire, 2) for purposes of executing a scheme or artifice to defraud.
See United States v. Mann,
Defendants next argue that the trial court erred in admitting evidence of the truthful character of three of the government’s witnesses before the witnesses’ credibility had been challenged, contrary to Fed.R.Evid. 608(a)(2). Rule 608(a)(2) provides that “evidence of truthful character is аdmissible only after the character of the witness for truthfulness has been attacked.” On direct examination of each of these three witnesses, the government elicited testimony concerning the existence of plea and cooperation agreements between these witnesses and the government. The witnesses further testified concerning the provisions of these agrеements requiring them to testify truthfully and subjecting these witnesses to prosecution for perjury if their testimony was untruthful.
Because defendants did not raise an objection at trial to the admission of this evidence, we will not disturb the defendants’ convictions absent a showing of plain error. Fed.R.Crim.P. 52(b);
see also United States v. Young,
The circuit courts are divided on the issue of when the government may present evidence of the truthfulness provisions of a witness’s plea or cooperation agreement with the government. The majority of circuits allow the government to admit evidence of the truthfulness provisions of an agreement on direct examination оf a witness, prior to any challenge to the witness’s credibility.
See United States v. Drews,
*1030
F.2d 90, 95 n. 3 (D.C.Cir.1989) (witness’s testimony that he was ordered by the court to offer his full cooperation as part of a plea bargain did not serve to impermissibly bolster the witness’s testimony),
petition for cert. filed, No.
89-6943 (Mar. 16, 1990). These courts have noted that evidence concerning a plea agreement and its provisions may have both a bolstering and an impeaching effect on the witness’s credibility.
See, e.g., Drews,
The Second Circuit, however, has held that, while the government may present evidence of the existence of an agreement and the witness’s understanding of that agreement prior to any challenge to the witness’s credibility, it is error for the government to introduce evidence of the agreement’s truthfulness requirements pri- or to a challenge to the witness’s credibility.
See United States v. Cosentino,
The Second Circuit has determined that the existence of an agreement impeaches, rather than bolsters, the witness’s credibility and has further determined that it is necessary to allow the government to establish the existence of an agreement between the government and the witness on direct examination, in order to prevent the jury from improperly inferring, when the agreement is brought up on cross-examination, that the government has tried to conceal that fact.
See, e.g., Cosentino,
In light of the dual nature of a plea or cooperation agreement in both impeaching
*1031
and bolstering the credibility of a witness,
see Bowie,
Next, both defendants assert the sentencing court erred in refusing to give defendants credit on their sentences for time spent in a halfway house as a condition of their release on bоnd prior to the commencement of their sentences. “The [United States] Attorney General has the initial discretion to credit a prison term with time spent in custody prior to commencement of sentence. A defendant must therefore exhaust his administrative remedies with the Attorney General before seeking review.”
United States v. Woods,
Finally, defendant Lord challenges the district court’s determination, in applying the sеntencing guidelines, denying Mr. Lord a downward adjustment for being a minor participant in the fraudulent scheme. The sentencing guidelines provide for a two-level downward adjustment if the defendant was a minor рarticipant in the criminal activity for which he was convicted. United States Sentencing Commission, Guidelines Manual, § 3B1.2(b). A minor participant is any participant who is less culpable than most of the other participants, but whose role cannot be described as minimal. Commentary to Sentencing Guidelines, § 3B1.2. A minimal participant is one who is among the least culpable of those involved in the criminal activity, in light of his lack of knowledge or understanding of the scope and structure of the criminal enterprise and the activity of the other individuals involved. Id.
This court reviews a sentencing court’s factual determinations under a clearly erroneous standard.
See United States v. Beaulieu,
The judgments of the United States District Court for the District of Colorado are AFFIRMED.
Notes
. After examining thе briefs and appellate record, this panel has determined unanimously that oral argument would not materially assist the determination of these appeals. See Fed.R. App.P. 34(a); 10th Cir.R. 34.1.9. The cases are *1029 therefore ordered submitted without oral argument.
. We note that the Ninth Circuit has held that the admission of the truthfulness provisions of an agreement between the government and a witness into evidence during direct examination amounts to improper vouching for the witness’s credibility by thе government.
See United States v. Lew,
