OPINION
Jаmes King (“King”) and Juan Ramirez-Mendoza (“Ramirez-Mendoza”) appeal from their convictions and their sentences for drug trafficking and conspiracy. They challenge the sufficiency of the evidence, the use of a tape transcript during closing argument, and their sentences, raising an Apprendi challenge to the failure to allege the drug amount and Ramirez-Mendoza’s prior conviction as elements of the offense. For the reasons that follow we affirm the convictions and sentences of both King and Ramirez-Mendoza.
I.
In 1998, the Drug Enforcement Administration (“DEA”) and the United States Postal Inspection Service began an investigation of a drug operation that was functioning through the mail. The first suspect identified was David Clark (“Clark”) in Tennessee, and by intercepting a cash package from Clark, investigators located Tami Butterfas (“Butterfas”), the recipient, in California. Investigators then intercepted a methamphetamine shipment to Clark, and on August 15, 1998, Clark was arrested after picking up the package. He cooperated, and investigators found in his day planner contact information for the two defendants in this case, Ramirez-Mendoza and King.
In September 1998, agents confronted Butterfas, who cooperated and made recorded telephone calls to King and Ramirez Mendoza. With King and his wife Valerie, Butterfas discussed how to “collaborate” on their stories to authorities about the Kings’ post office boxes, thе mailing of the packages, and their acquaintance with Clark. In the conversation, Butterfas mentioned that the DEA had visited her, and she asked if King had gotten “rid of’ “everybody’s” numbers, which King said he would do.
With Ramirez-Mendoza, Butterfas discussed a drug deal, and she protested when he said she had to give him the money first. Ramirez-Mendoza explained the precaution by saying “I know you got trouble, you in trouble with the people ... with the people you are sending the mail.”
After a superseding indictment was returned against eight defendants on September 15, 1998, King and Ramirez-Mendoza were arrested. Five other defendants entered guilty pleas. The jury trial ■ of King and Ramirez-Mendoza, along with a conspirator who was subsequently acquitted, began on August 9, 1999. Thе government relied principally on the Butterfas tapes and testimony by Butterfas and Clark, who explained how the conspiracy operated. Ramirez-Mendoza supplied methamphetamine to But-terfas, who for the last five or six months before her arrest had King ship it to Clark for distribution in Tennessee and North Carolina. She paid him $400 for each package shipped. The government introduced into evidence several of the packages’ labels with King’s hand *370 writing. Clark on at least one occasion dealt directly with Ramirez-Mendoza, and according to Butterfas, Clark at least five or six times sent the money directly to King. Eventually Butterfas started giving King the money to purchase the drugs from Ramirez-Mendoza.
King and Ramirez-Mendoza were convicted by a jury on August 13, 1999, of conspiracy to distribute and possession with intent to- distribute methamphetamine, in violation of 21 U.S.C. §§ 846 and 841. King was sentenced to 151 months of imprisonment with five years of supervised release. Ramirez-Mendoza was sentenced to 240 months’ imprisonment with ten years of supervised release.
II.
Both King and Ramirez-Mendoza challenge the sufficiency of the evidence underlying their convictions. We review such claims to determine “whether, after viewing the evidence in the light most favorable to the prosecution,
any
rational trier of fact could have found the essential elements of the crime beyond a reasonable doubt.”
United States v. Wright,
To prove a drug conspiracy under 21 U.S.C. § 846, “the government must prove that a conspiracy existed, that the accused knew of the conspiracy, and that he knowingly and voluntarily joined it.”
United States v. Ledezma,
a) King
King argues that the evidence is insufficient to support his conviction for conspiracy because the proof does not establish that he knew of the conspiracy or that the packages whose labels he addressed contained drugs (he says he thought they contained equipment parts used in a logging business). He also adopts, in his reply brief, Ramirez-Mendoza’s argument that the Butterfas tapes cannot provide evidence of his agreement to join the conspiracy.
“A trier of fact may infer knowledge of and participation in the common purpose and plan of a conspiracy based on defendant’s actions and reactions to the circumstances.”
United States v. Barrett,
*371 The Butterfas tapes also reveal King’s awareness of a conspiracy. Butterfаs in conversation with King says she fears conspiracy charges. In addition, King and his wife and Butterfas discuss what to say about co-conspirator David Clark. King’s agreement to delete “everybody’s” numbers from his planner is simply incompatible with King’s professed ignorance of the conspiracy.
King’s claim that he thought the packages only contained logging equipment is equally implausible in light of the tapes, where Butterfas speculates, after mentioning that the DEA visited her, that “they” intercepted packages. King expresses no surprise, and goes on to discuss the packages with Butterfas. The government also introduced evidence that King received $400 each time he mailed a package for Butterfas, an amount inconsistent with King’s professed belief in their “innocent” contents. Testimony and tapes provided ample evidence of King’s knowledge of the conspiracy and of the packages’ drug contents.
King in his reply brief adopts an argument made by Ramirez-Mendoza, namely, that the taped conversation between him and Butterfas cannot be evidence that he agreed to participate in a conspiracy because Butterfas had become a government informant by the time of the tapes. Although a person acting as a government agent cannot be a coconspirator, “his meetings and conversations with defendants can be evidence of conspiracy among thе defendants.”
United States v. Esparsen,
The tape, along with testimony by But-terfas and Clark, provided reasonable jurors sufficient evidence to conclude that King had agreed to cooperate with others in the conspiracy.
b) Ramirez-Mendoza
Ramirez-Mendoza challenges the sufficiency of the evidence of his knowledge of and participation in the charged conspiracy; he suggests that there were separate conspiracies and the government has not proven that he was involved in the Tennessee conspiracy listed in the indictment. He also challenges the sufficiency of the evidence that he entered into a conspiracy agreement.
Ramirez-Mendoza admits that he sold drugs in California, but contends that he never traveled to Tennessee and did not know that Butterfas was sending his drugs to Tennessee. The indictment alleged that the defendants participated in a conspiracy “in the Eastern District of Tennessee and elsewhere” to distribute and to possess methamphetamine. Even if Ramirez-Mendoza did not know that Tennessee was the drugs’ final destination, he may still be guilty of the conspiracy. The government need only show that “the defendant knew the essential object of the conspiracy,”
United States v. Hernandez,
The essential object of this conspiracy would have beеn the distribution of methamphetamine. Ramirez-Mendoza acknowledges that he sold methamphetamine to Butterfas and King, and there was evidence that Ramirez-Mendoza was aware of the conspiracy. In his conversation with Butterfas, Ramirez-Mendoza says, “I know you got trouble, you in trouble with the people [inaudible].” Moreover, Butterfas testified that she told Ramirez-Mendo
*372
za that she was sending the drugs to North Carolina and Tennessee to her “people.” Ramirez-Mendoza vaguely challenges this testimony by pointing out that Butterfas waited until the day before trial to inform the government that Ramirez-Mendoza knew that the drugs he was selling her were being distributed in Tennessee and North Carolina. If this is an attack on the credibility of the evidence, then it fails since, as discussed above, credibility attacks do not go to the sufficiency of the evidence.
Sanchez,
Ramirez-Mendoza attempts to raise a multiple conspiracy issue by asserting that “at best there is a separate conspiracy.” He does not, however, offer any facts in support of his theory that there were multiple conspiracies but rather recites factors used by the Ninth Circuit to determine whether a defendant knowingly participated in a single overall conspiracy. We have addressed the multiple conspiracy issue in thе context of a drug chain conspiracy: “[I]n determining whether the evidence showed a single conspiracy or multiple conspiracies, it must be remembered that in a drug ‘chain conspiracy’ ..., ‘it is enough that each member of the conspiracy realizes that he is participating in a joint enterprise, even if he does not know the identities of many of the participants.’ ”
United States v. Odom,
In the instant case, Ramirez-Mendoza was directly in contact with Clark and King, and Clark was in Tennessee. Even if the government had not shown Ramirez-Mendoza’s connections to Clark, under our standard, it is enough if a defendant knows he is participating in a joint enterprise. Ramirez-Mendoza in the taped conversation with Butterfas refers to her “people” who have been in trouble with the law; he was aware that the drugs he was selling her were being distributed. There was sufficient evidence to show that Ramirez-Mendoza knowingly participated in the charged conspiracy. 1
III.
King argues that the district court erred by allowing the government in its closing argument to read from the transcript of a tape that had been introduced during trial. King claims that the references to the transcript led the jury to believe that the transcript accurately reflected the conversation that took place.
“As with tape recordings of communications, the use of a transcript of a recorded communication during trial is within the sound discretion of the trial court.”
United States v. Wilkinson,
In the instant case, the prosecution mentioned the Butterfas King transcript in rebuttal during closing argument. King’s counsel objected, 2 but the court overruled the objection, noting that it was permissible to refer to the transcript in closing argument. Government counsel continued to refer to the transcript:
Ms. Butterfas says, okay, listen, have you heard anything. What does Mr. King say? He says, not about what. He says, uh-uh, what is going on. She then tells him that DEA came here yesterday. He says, did he? She says, do you know, she says she told DEA or DEA asked her do you know David Clark. She told him I have known him for years and DEA says, well, why are you receiving mad from him and Jim King says, yeah. She goes on to say, I said, yeah. They said, do you know Jim King. Known him for years, me and. Kirk used to live in Lebec. Jim King says, yeah. And then for some reason the very next thing Jim King says is, the only time I received mail from him was once up there. That being in Lebec. Ladies and gentlemen, that is an acknowledgment on behalf of a defendant to be tried by you that he was receiving mail from David Clark.
The attorney continues to quote, paraphrase, аnd comment on the transcript, discussing the post office boxes and David Clark. Before submitting the case to the jury, the district court instructed the jury that the transcript was not evidence and the tape controlled.
In Scarborough, the trial court, after reviewing tapes of co-conspirators and the government-made transcript, allowed the jury to use the transcript as a guide while listening to tapes. We rejected defendant’s challenge to this practice for a number of reasons:
[AJlthough defendant has questioned the accuracy of the tapes, he has not shown that the transcripts were inaccurate in any way or how he was prejudiced. The District Court instructed the jury that the transcript is not evidence and rеpeated this instruction before giving the transcript to the jury during deliberations. The court also, at the request of defendant, told the jury that the transcript represented the government’s version of the tape.
Scarborough,
King relies on
United States v. Robinson,
*374 [I]n the absence of a stipulation, we hold that the transcriber should verify that he or she has listened to the tape and accurately transcribed its content. The court should also make an independent determination of accuracy by reading the transcript against the tape. Where, as here, there are inaudible portions of the tape, the court should direct the deletion of the unreliable portion of the transcript. This, however, assumes that the court has predetermined that unintelligible portions of the tape do not render the whole recording untrustworthy.
Id.
at 878-79;
see also Wilkinson,
In the instant case, defendants have not alleged that the inaudible portions of the transcript are so great as to render the entire transcript untrustworthy, as in Robinson. The government had Butterfas testify as to the accuracy of the transcripts, which were of her own conversations, the court cautioned the jury that the attorneys’ arguments were not evidence, and the transcript was not sent back with the jury during deliberations. Defendants hаve not demonstrated prejudice, and the district court did not abuse its discretion in allowing the government to refer to the transcript.
IV.
King and Ramirez-Mendoza argue that the drug quantity upon which their sentences were based should have been alleged in the indictment and proven to the jury. They rely on
Jones v. United States,
Neither defendant raised a
Jones, Apprendi
issue at trial or at sentencing
(Apprendi
was decided after their sentencing.) We therefore review for plain error. Fed.R.Crim.P. 52(b);
United States v. Neuhausser,
[B]efore an appellate court can correct an error not raised at trial, there must *375 be (1) error, (2) that is plain, and (3) that affects substantial rights. If all three conditions are met, an appellate court may then exercise its discretion to notice a forfeited error, but only if (4) the error seriously affects the fairness, integrity,' or public reputation of judicial proceedings.
Johnson,
a) Ramirez-Mendoza
Ramirez-Mendoza makes an Apprendi-Jones challenge to his term of imprisonment. He received 240 months (twenty yеars) of imprisonment and ten years of supervised release under 21 U.S.C. § 841(b)(1)(A). Ramirez-Mendoza did not object to the presentence report (“PSR”) finding that he was responsible for more than 300 grams but less than one kilogram of actual methamphetamine, or that he had prior convictions, so the district court sentenced him based on these findings. The statute provides a mandatory minimum of twenty years for a defendant convicted of possessing 50 grams or more of pure methamphetamine if the defendant has a prior conviction for a felony drug offense. 21 U.S.C. § 841(b)(1)(A). Ramirez-Mendoza argues that under Apprendi and Jones, both the drug quantity and his prior conviction were elements of the offense that had to be proven to the jury. 4
If no drug quantity had been specified, the statute would provide for a maximum prison term of twenty years’ imprisonment and at least three years of supervised release, unless defendant had a prior felony drug conviction, in which case the maximum would be thirty years, with at least six years of supervised release.
See
21 U.S.C. § 841(b)(1)(C). While Ramirez-Mendoza’s sentence falls below the maximum term authorized by 21 U.S.C. •§ 841(b)(1)(C), this court has held that “[aggravating factors, other than a prior conviction, that increase the penalty from a nonmandatory minimum sentence to a mandatory minimum sentence, or from a lesser to a greater minimum sentence, are now elements of the crime to be charged and proved.”
United States v. Ramirez,
b) King
King challenges his supervised release term. King’s sentence was based on the PSR’s determination of the drug quantity as at least 300 grams but less than one kilogram of actual methamphetamine. King objected only that the amount was closer to the 300 gram level than the one kilogram level. He received 151 months of imprisonment and five years of supervised release under 21 U.S.C. § 841(b)(1)(A), which provides that the term of supervised release for possessing at least 50 grams of pure methamphetamine is “at least 5 years” if there was no prior conviction. 21 U.S.C. § 841(b)(1)(A).
In a case where a quantity of drugs was not alleged in the indictment or proven tо a jury, this court has determined that the “prescribed statutory maxi
*376
mum” is set in the statutory provision for drug offenses where no quantity is specified.
See
21 U.S.C. § 841(b)(1)(C);
Ramirez,
In view of our recent decisions we conclude that an
Apprendi
error occurred in King’s sentencing. In
United States v. Strayhorn,
Similarly, in
Ramirez
we held that “[aggravating factors, other than a prior conviction, that increase the penalty from a nonmandatory minimum sentence to a mandatory minimum sentence,
or from a lesser to a greater minimum sentence,
are now elements of the crime to be charged and proved.”
Ramirez,
Garcia was sentenced to 135 months’ imprisonment under the sentencing guidelines based on the district court’s determination that he was responsible for 2,499 kilograms of marijuana. Prior to sentencing Garcia had admitted his responsibility for 625 kilograms of marijuana, but denied he was responsible for a greater amount. The district court’s determination that Garcia was responsible for a larger quantity of drugs increased the statutory sentencing range to which Garcia was susceptible from between five years and forty years of imprisonment, 21 U.S.C. § 841(b)(1)(A), to between ten years and life imprisonment. 21 U.S.C. § 841(b)(1)(B). Garcia argued that the district court’s drug quantity determination constituted an Apprendi error as it increased the range of sentences to which he was exposed. We disagreed.
Although the district court’s findings here brought the defendant within the sentencing range of § 841(b)(1)(A) (specifying 10 years to life), which is a higher range than he explicitly admitted to at his allocution, see § 841(b)(l)(B)(specifying 5-40 years), the sentence imposed here was not at the bottom of the higher statutory range, as it was in Ramirez. Thus nothing indicates that the district court thought itself constrained by a specific statute to impose the sentence it did. The final sentence — imposed pursuant to the Guidelines аnd supported by findings of fact appropriately found by a preponderance of the evidence — offends neither Apprendi [n]or Ramirez.
Garcia,
In
Stafford
itself, defendant pleaded guilty and stipulated to being responsible for 235.42 grams of cocaine-base and 14.48 grams of cocaine. He was sentenced to 188 months’ imprisonment pursuant to the sentencing guidelines. Stafford later argued that the government had failed to prove that he was responsible for сocaine base, rather than cocaine in its powder form. This difference in form affected the statutory sentencing range to which Stafford was exposed, taking him out of the default provision contained at 21 U.S.C. § 841(b)(1)(C) (specifying up to twenty years’ imprisonment) and subjecting him instead to 21 U.S.C. § 841(b)(1)(A) (ten year minimum). Although we rested our
*378
holding on the fact that Stafford’s substantial rights had not been affected by any error at sentencing, we also noted that “[d]efendant’s sentence d[id] not run afoul of
Apprendi,
because it [wa]s both below the 20 year statutory maximum established by the ‘catchall’ provision at § 841(b)(1)(C), and above the 10 year statutory minimum found at § 841(b)(1)(A).”
Stafford,
In the present case, King’s 151 month term of imprisonment was below the twenty year statutory maximum established by § 841(b)(1)(C), and above the 10 year statutory minimum found at § 841(b)(1)(A). Under such circumstances we do not believe that an Apprendi error occurred as to this portion of King’s sentence. In any event, as we will discuss below, we do not believe that King’s substantial rights were affected by any error at sentencing.
c) Were the substantial rights of the defendants affected by the Apprendi errors?
Ramirez-Mendoza, in whole, and King, in part, succeed in satisfying the first two elements of plain error analysis: that an error occurred and that it was plain. The remaining question is whether the errors in sentencing affected the substantial rights of King and Ramirez-Mendoza — the third prong of plain error analysis. “This third step is akin to the harmless error analysis employed in preserved error cases, which аsks whether a rational jury would have found the defendant guilty absent the error.”
United States v. Candelario,
In the present case, the government notes that Ramirez-Mendoza did not contest the drug quantity determination contained in his PSR; that King objected only that the amount in question was closer to 300 grams than one kilogram of actual methamphetamine; and that the testimony of a forensic chemist that 82.8 grams of actual methamphetamine was found in one intercepted package was undisputed. In the presence of such uncontroverted evidence as to the quantity of drugs involved, the government argues that we should conclude that any Apprendi error failed to affect the defendants’ substantial rights.
*379 In Stafford, defendant was sentenced to 188 months’ imprisonment for possession with intent to distribute cocaine in violation of 21 U.S.C. § 841(a)(1). Upon appeal, he raised the issue of an Apprendi error in sentencing on the grounds that his indictment was silent as to the type or quantity of cocaine. We noted that even if the omission of such information constituted plain error, any error had failed to affect defendant’s substantial rights:
The reasoning of Pease and Duarte applies with full force here. We already have found that Defendant effectively admitted the types and quantities of cocaine involved in the charged drug offense, both through his own affirmative statements, аnd by virtue of his failure to challenge the Government’s statements at the change-of-plea hearing and in the PSIR. Moreover, as in Duarte, Defendant here was repeatedly advised, both in the plea agreement and at the change-of-plea hearing, that a plea of guilty to this drug offense would expose him to a mandatory minimum 10 year term of imprisonment and a maximum term of life imprisonment, and the PSIR further emphasized this point by expressly citing the penalty provision at 21 U.S.C. § 841(b)(1)(A).
Stafford,
Here, too, the defendants failed to contest the drug quantity determinations contained in their PSRs but, in contrast to
Stafford,
their guilt was determined by the jury rather than through a plea agreement. A similar situation was recently considered by the Seventh Circuit in
United States v. Martinez,
Given the duration and scope of Martinez’s organization, the evidence was overwhelming that the amount of crack was far beyond 50 grams. No reasonable jury could conclude that the conspiracy involved under 50 grams of crack. Thereforе, because the evidence was more than sufficient to show an amount of crack which would allow for a life sentence, the error did not seriously affect the public integrity, fairness, or reputation of these proceedings, and we will not upset the verdict on plain error review.
Id. at 586. Although the Seventh Circuit’s decision rested on the fourth prong of plain error review rather than the third, we agree with their assumption that the means by which guilt is determined, whether a plea bargain or guilty verdict, does not affect our plain error review.
Based on our decision in Stafford and the Seventh Circuit’s decision in Martinez, we conclude that the substantial rights of the defendants were not affected by any Apprendi error which may have occurred during sentencing. Both defendants failed to object to thе drug quantity determinations contained in the PSRs despite being on notice that such determinations would affect the length of their sentences. Indeed, King merely objected that the amount in question was closer to 300 grams of actual methamphetamine rather than one kilogram. Moreover, it was the undisputed testimony of a forensic chemist that one package contained 82.8 grams of actual methamphetamine, an amount above *380 the 50 gram amount needed to trigger the defendants’ sentences under the applicable statutes. See 21 U.S.C. § 841(b)(1)(A). We therefore conclude that any errors in sentencing failed to affect the defendants’ substantial rights.
V.
King raises two additional claims which we may deal with briefly. He first contends that his supervised release term of five years is illegal because the maximum term of supervised release that may be imposed under 18 U.S.C. § 3583(b) is three years. King acknowledges that this statute conflicts with 21 U.S.C. § 841, which provides a minimum term of three years of supervised release if the drug quantity is not specified (and there is no prior conviction), 21 U.S.C. § 841(b)(1)(C), and a minimum term of five years if the quantity is 50 grams or more of pure methamphetamine. 21 U.S.C. § 841(b)(1)(A).
In
United States v. Page,
King also argues that his offense level should have been reduced based on his role as a minor or minimal participant. We review a district court’s denial of a mitigating role adjustment for clear error.
United States v. Owusu,
There is no clear error in the district court’s finding that King was neither a minimal nor a minor participant when he was knowingly involved with repeated shipments of drugs.
See Owusu,
VI.
The convictions and sentences of the defendants are affirmed.
Notes
. Ramirez-Mendoza argues that the taped conversation between him and Butterfas cannot be evidence that he agreed to participate in a conspiracy because Butterfas had become a government informant by tire time of the
tapes.
As noted above, the tapes nevertheless may be evidence of Ramirez-Mendoza's agreement to conspire with others.
Esparsen,
. The government had provided defendants with copies of the tapes and transcripts before trial, and defendants did not challenge the accuracy of the transcripts at trial or on appeal. At trial, the tapes were introduced into evidence, and the transcript was introduced as an exhibit; King's attorney objected to the transcript as cumulative, but not to its accuracy. On appeal, King claims that the tapes were difficult to understand, but he has not identified any portions of the transcript read in the closing argument that did not correspond to the tapes.
. Ramirez-Mendoza contends that the
Ap-prendi
argument is a challenge to the sufficiency of the indictment which should be reviewed de novo. We have not, however, construed
Apprendi
claims to be challenges to the sufficiency of the indictment and have used plain error review (even when
Apprendi
had not been decided at the time a defendant was tried and sentenced).
See Neuhausser,
.
Apprendi
made clear that prior convictions are sentencing factors and not elements to be proven to the jury,
Apprendi,
. King’s challenge to his supervised release term also survives our recent decision in United States v. Garcia, 252 F.3d 838 (6th Cir.2001). As will be discussed more fully below, Garcia limited the scope of Ramirez to cases in which the district court was constrained by the operation of a sentencing statute to impose a particular sentence. Garcia, 252 F.3d at 843. Here the operation of the statute raised the minimum supervised release term *377 faced by King to five years — the precise term of the sentence ultimately imposed on King. Under such circumstances, Garcia does not apply.