A jury convicted Vernard L. Green, Jr., of distributing crack cocaine, conspiracy to distribute crack cocaine, and using a communication device in connection with the conspiracy and distribution. Green appeals, raising multiple alleged evidentiary and sentencing errors by the district court and asserting that the evidence was insufficient to support his conviction. We affirm.
I
Vernard Green’s problems began when the Gary Response Investigative Team (GRIT), a task force of federal and state law enforcement officers, targeted for investigation one of Green’s customers, Ar-mondo Guzman, whom they suspected of trafficking in drugs in Gary, Indiana. GRIT enlisted the help of Danny Cox, an informant who had cooperated in other GRIT investigations after GRIT caught him selling cocaine to undercover agents.
GRIT asked Cox to attempt to make a controlled purchase from Guzman, and on April 10, 1998, Cox went to Guzman’s home and asked for an ounce of crack cocaine. Guzman said he would have to contact his source, and placed a telephone call. A short time later, an individual arrived and gave the cocaine to Guzman, who *688 then sold it to Cox. The GRIT officers conducting surveillance were too far away to see who delivered the cocaine to Guzman.
Several days later, Lieutenant Huttle and two other GRIT officers arrested and questioned Guzman. According to Hut-tie’s written report of that interview, Guzman identified a man known as “Butter” as his source of cocaine. Guzman told the agents that he purchased cocaine from “Butter” about 100 times, usually in quantities of either an eighth of an ounce or an ounce.
Vernard Green was then questioned by three GRIT officers, including Indiana State Trooper John Jefferson, about the events on April 10. According to Jefferson’s report of that interview, Green admitted that in response to Guzman’s page, he delivered crack cocaine to Guzman’s house. Green identified his source as John Vinson, and agreed to try to make a controlled purchase of crack from him. Although he placed a call to Vinson and identified himself as “Butter,” he refused to give any further cooperation. He was arrested and indicted on charges of distributing crack cocaine, conspiracy to distribute crack cocaine, and using a communication device in connection with the conspiracy and distribution.
At trial, Cox and Guzman identified Green as the one who made the April 10 delivery to Guzman. Another witness, Clifton Rock, testified that Green was his source for cocaine, and testified that he also saw Green sell drugs to Herman Hicks, Ann Kelly, and Vincent Hill. Three GRIT agents testified that Green had admitted to them that in April 1998 he delivered an ounce of cocaine to Guzman’s house in response to Guzman’s page, and that Vinson was Green’s source. When Green took the stand, he stated that he went to Guzman’s house in April in response to Guzman’s page, but he denied delivering crack cocaine, making incriminating statements to the GRIT officers, and any involvement with Vinson. A jury convicted Green on all three charges.
At sentencing, the trial judge found Green responsible for more than 500 grams of crack cocaine, based in large part on Guzman’s statement about his history of purchases from Green. The court increased Green’s offense level based on its determination that Green had committed perjury during the trial, and denied Green’s request for a downward departure based on his employment and family circumstances. The court sentenced Green to concurrent sentences of 235 months’ imprisonment on the first two counts (conspiracy and distribution) and 48 months on the third (using a communication device to facilitate the conspiracy and distribution).
II
A
Green argues that his conviction should be reversed for four reasons. First, Green contends that the district court erred in admitting, as past recollection recorded, law enforcement officers’ written summaries of their interviews with Green and Guzman. He challenges the admission of the reports and the statements attributable to Green and Guzman within those reports. Second, he claims that the government improperly bolstered Cox’s credibility by eliciting testimony about Cox’s cooperation in other prosecutions. Third, he argues that testimony concerning his prior drug transactions was inadmissible under Federal Rule of Evidence 404(b). Finally, Green claims that the evidence was insufficient to support his convictions. We examine each of these contentions in turn.
*689 1. The officers’ written summaries.
The district court allowed Trooper Jefferson to read to the jury the written summary he prepared of his interview of Green, and allowed Lieutenant Huttle to read to the jury his summary of the interview of Guzman. Both written summaries are the officers’ out-of-court declarations, offered to prove the matter asserted in them, so are hearsay. See Fed.R.Evid. 801(c). The district court admitted those summaries under Federal Rule of Evidence 808(5), the hearsay exception for past recollection recorded, which allows memoranda or records meeting the criteria of the Rule to be read to the jury, but not received as an exhibit. Green made a timely objection to the admission of the reports, so our review is for abuse of discretion.
United States v. Lewis,
Green first contends that Jefferson’s interview summary does not meet the criteria of Rule 803(5) because Jefferson did not prepare the summary until 11 days after his interview with Green. Rule 803(5) requires that the memorandum be made by the witness “when the matter was fresh in the witness’ memory,” but we have declined to adopt any bright-line rule to measure whether a particular delay is too long.
Lewis,
Green next contends that the assertions attributed to Guzman and Green within the reports should be excluded because he and Guzman did not adopt the reports. We have held that when a witness’s statement is recorded by another, both the witness and the one transcribing the statement must testify as to the accuracy of the report to establish that the statement is the witness’s past recollection recorded under Rule 803(5).
United States v. Schoenborn,
However, adoption of the assertions by Green and Guzman is not required if there
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is another basis for admitting them. This is because statements such as these that comprise multiple levels of potential hearsay are admissible if each part is admissible.
See
Fed.R.Evid. 805;
United States v. Severson,
As to the assertions attributed to Guzman in Huttle’s report, the government offered those as Guzman’s prior consistent statements. A statement is not hearsay, and admissible as a prior consistent statement under Rule 801(d)(1)(B), if it meets the following four requirements:
1) the declarant testifies at trial and is subject to cross-examination; 2) the pri- or statement is consistent with the declarant’s trial testimony; 3) the statement is offered to rebut an express or implied charge of recent fabrication or improper motive; and, 4) the statement was made before the declarant had a motive to fabricate.
United States v. Stoecker,
Putting aside the first requirement for a moment, we conclude that the district court was within its discretion in determining that Guzman’s statements to Huttle were admissible under Rule 801(d)(1). The statements were consistent with Guzman’s trial testimony, and were offered to rebut Green’s counsel’s attempt in cross-examination to show that, because of his plea agreement, Guzman had a motive to fabricate.
See Stoecker,
Returning to the requirement that the declarant be available for cross-examination, Green contends that it was error to admit Guzman’s prior statement after the conclusion of Green’s cross-examination of Guzman and during the testimony of Lieutenant Huttle. In
United States v. West,
At the time
West
was decided, we acknowledged that our interpretation of Rule 801(d)(1)(B) differed from the interpretation of six other circuits that permit a third party to testify about another witness’s prior consistent statement, so long as the witness who made the out-of-court statement is available for cross-examination at some time during the trial.
Id.
at 686 (citing
United States v. Provenzano,
The justification we provided in
West
was that Rule 801(d)(1)(B) requires not only that the declarant generally be available for cross-examination, but that he be available for cross-examination about the statement.
West,
That the requirement articulated in
West
is not contained in nor apparent from the Rule itself may explain why West has not been mentioned in later decisions of this court approving the admission of prior consistent statements that were elicited not from the declarant but from the person to whom the statement was made.
See United States v. Ruiz,
We therefore believe that it is time to join our sister circuits and hold that Rule 801(d)(1)(B) does not bar the introduction of a prior consistent statement through the testimony of someone other than the declarant, so long as the declar-ant is available for cross-examination about the statement at some time during trial. 4 There is no indication that Green was prevented from recalling Guzman for cross-examination about the assertions attributed to Guzman in Huttle’s report, and because those assertions meet the other requirements for admission under Rule 801(d)(1)(B), the district court did not abuse its discretion in allowing Huttle’s report to be read to the jury.
2. Evidence regarding Cox’s prior cooperation.
Green also contends that the district court erred in permitting testimony about Cox’s cooperation with the government’s investigation and prosecution of two individuals unrelated to Green’s case. He claims that this testimony was improper bolstering of Cox’s credibility and barred by Federal Rule of Evidence 608(b).
We begin with a few general comments. First, “bolstering” is the practice of building up a witness’s credibility before impeachment has been attempted.
United States v. Lindemann, 85
F.3d 1232, 1242 (7th Cir.1996);
United States v. LeFevour,
Second, Federal Rule of Evidence 608(b) bars the use of extrinsic evidence of “[s]pecific instances of the conduct of a witness, for the purpose of attacking or supporting the witness’ credibility.” Fed. R.Evid. 608(b). However, we have held that if evidence of the witness’s cooperation in other investigations is directed at rebutting allegations of the witness’s bias, and not at his character for truthfulness in general, the limitations of Rule 608(b) do not apply.
Lindemann,
Turning to the specific testimony in this case, we note that Green
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made no objection at trial to the testimony that he now complains was improper (with one exception, which we will address in a moment), and our review is therefore for plain error.
Penny,
Green did make a timely objection to Bookwalter’s statement that the other trial in which Cox testified resulted in conviction, and so we review the district court’s decision to admit that statement for abuse of discretion.
Curry,
But given the government’s concession, we decline to explore the question of whether the district court abused its discretion in this case by admitting evidence of the convictions that resulted from Cox’s testimony. Instead, we agree with the government that the error, if any, was harmless because of the overwhelming evidence of Green’s guilt.
See
Fed.R.Crim.P. 52(a). The most significant evidence provided by Cox was his identification of Green as the person who arrived at Guzman’s home immediately before Guzman delivered the cocaine to Cox on April 10. But this identification was confirmed not only by Guzman’s testimony, but by three GRIT agents who testified that Green confessed to that incident — testimony that Green does not challenge on appeal. Giv
*694
en this testimony, and other corroborating evidence, we find that even if it was error to admit testimony that Cox’s cooperation in other cases resulted in convictions, the error was harmless.
See Curry,
3. Evidence of Green’s prior drug transactions.
Green next contends that the district court improperly admitted Clifton Rock’s testimony that he purchased from Green an average of about 1 ounces of cocaine per week, and that he saw Green sell cocaine to other individuals, during a period ending more than a year before the conspiracy charged in this case. Evidence of other wrongs is admissible under Federal Rule of Evidence 404(b) if the evidence: (i) is directed toward establishing a matter in issue other than the defendant’s propensity to commit the crime charged; (ii) shows that the other act is similar enough and close enough in time to be relevant; (iii) is sufficient to support a finding that the defendant committed the other act; and (iv) has probative value not outweighed by the danger of unfair prejudice.
United States v. Williams,
As to the first prong of the test, we have held on numerous occasions that when a defendant is charged with a specific intent crime (here, conspiracy to distribute cocaine), evidence of the defendant’s prior drug transactions may be relevant to show knowledge and intent-purposes distinct from simply showing the defendant’s propensity for drug dealing.
United States v. Jones,
Whether the evidence meets the second prong of the test, similarity and proximity, is evaluated in relation to the purpose for which the evidence is offered.
United States v. Ruiz,
Rock’s testimony that he sold drugs to Green and saw Green sell drugs to others is sufficient to support a jury’s finding that Green did in fact engage in that conduct, and therefore the third prong of the test is satisfied, notwithstanding Green’s assertions about Rock’s credibility.
See United States v. Smith,
Finally, as to the fourth prong, we find no error in the district court’s determination that the evidence was not unfairly prejudicial when weighed against its probative value, particularly in
*695
light of the district court’s instruction limiting the jury’s consideration of the evidence to the narrow purpose for which it was offered.
See United States v. Denberg,
4. Sufficiency of the evidence.
Green’s final challenge to his conviction is that the trial evidence was insufficient to support his conviction, specifically, that there was insufficient evidence that it was Green who participated in the transactions with Guzman in April 1998. Challenges based on the sufficiency of the evidence are rarely successful.
See United States v. Sanchez,
B
We turn now to Green’s three challenges to his sentence, specifically, the district court’s calculation of drug quantity, its enhancement of the sentence for obstruction of justice, and its refusal to grant a downward departure for family circumstances and employment. We have examined each of these challenges and find them to be without merit. First, there was no clear error in the district court’s calculation of drug quantity, which was supported by sufficiently reliable evidence, including Guzman’s testimony and statements about his history of purchases from Green.
See United States v. Durham,
Ill
For the foregoing reasons, the judgment of the district court is AffiRmed.
Notes
. The government contends that Green made no objection at trial to the admission of Hut-tie's report as past recollection recorded, and therefore that our review is for plain error. We conclude, however, that Green’s objections — while not a model of clarity— were adequate to preserve the issues that he is advancing on appeal regarding whether the assertions attributable to Guzman in Huttle’s report are admissible as a prior consistent statement.
. Federal Rule of Evidence 801(d)(1) defines prior consistent statements as not hearsay if "[t]he declarant testifies at the trial or hearing and is subject to cross-examination concerning the statement, and the statement is ... (B) consistent with the declarant's testimony and is offered to rebut an express or implied charge against the declarant of recent fabrication or improper influence or motive....''
. In any event, at the time Guzman made the statement, Guzman had not yet entered into a cooperation agreement with the government, and a reasonable person could have concluded that the motive to fabricate did not arise until the cooperation agreement. Therefore, Green cannot show that the court abused its discretion in determining that this requirement of Rule 801(d)(1)(B) was met.
See Fulford,
. Because this holding overrules part of our decision in West, this opinion has been circulated to all judges in regular active service in accordance with Circuit Rule 40(e). No judge voted to hear the case en banc.
. The same is true for the testimony that the government later elicited from Cox, which simply confirmed the information already elicited by Green concerning Cox's cooperation in the earlier investigation.
. Green also relies on
United States v. Taylor,
. Green also complains that the government did not disclose, until the day before Rock testified, that he would say that he saw Green sell cocaine to Hicks, Kelly, and Hill. No objection was made to the timeliness or adequacy of the government’s pretrial notice describing Rock's testimony, so our review of this point is for plain error.
See United States v. Robinson,
