The opinion of the court was delivered by: Kearse, Circuit Judge
Before: KEARSE, CALABRESI, and SACK, Circuit Judges.
Defendants Jaime Chavez and Anastacio Acosta appeal from judgments entered in the United States District Court for the Southern District of New York following a jury trial before Gerard E. Lynch, Judge, convicting each defendant of conspiracy to distribute and possess with intent to distribute more than five kilograms of cocaine, in violation of 21 U.S.C. § 846 (count one), and convicting Chavez of possession, in furtherance of the cocaine trafficking conspiracy, of a firearm equipped with a silencer, in violation of 18 U.S.C. §§ 924(c)(1)(A) and (c)(1)(B)(ii) (count two). Chavez was sentenced principally to 300 months' imprisonment on count one and to 360 months' imprisonment on count two-the statutory minimum for that count-to be served consecutively to the term imposed for count one, for a total prison term of 660 months. Acosta was sentenced principally to 198 months' imprisonment. On appeal, Chavez and Acosta contend that the evidence was insufficient to support their convictions and that there were trial errors, and they challenge their sentences. Finding no basis for reversal, we affirm. We write principally to address Chavez's contention that the district court erred in concluding that, having determined an appropriate sentence for him on count one, it had no authority to reduce that sentence on account of the severity of the sentence it was required to impose for count two.
The indictment on which Chavez and Acosta were tried alleged that they were members of a narcotics conspiracy that operated in various areas, including New York City and California, from approximately October 2001 through May 2003. Other alleged members of the conspiracy included Gregorio Barraza, his brothers Daniel Barraza and Jose Luis Barraza, and cooperating witness Nicholas Ibarra. The government's evidence at trial, discussed in greater detail in Part II.A. below, consisted principally of (a) recordings of telephone conversations between Chavez and other conconspirators, and (b) the testimony of Ibarra who, inter alia, described the organization's narcotics distribution operation in New York and interpreted some of the coded terms used in conconspirators' telephone conversations. The government also introduced in evidence a pistol, equipped with a silencer, that had been seized from Chavez's apartment.
The jury found both Chavez and Acosta guilty of conspiracy to distribute and possess with intent to distribute more than five kilograms of cocaine. It found Chavez guilty of possessing the silencer-equipped pistol in furtherance of that drug trafficking conspiracy.
The district court sentenced Acosta principally to 198 months' imprisonment ( see Part II.C.2. below). The court sentenced Chavez principally to 300 months' imprisonment on count one, followed by 360 months' imprisonment-the statutory mandatory minimum sentence for his conviction on count two-for a total of 660 months' imprisonment ( see Part II.B. below).
On appeal, both defendants contend principally (1) that the evidence was insufficient to support their convictions, and (2) that their sentences were unreasonable. They also advance various other contentions, including that statements made by the government in summation were improper and that the district court should have given an accomplice-witness instruction in the language requested by Acosta. We find no merit in any of defendants' contentions; only the evidentiary and sentencing challenges warrant discussion.
A. Sufficiency of the Evidence
Both Chavez and Acosta contend that the government's evidence at trial was insufficient to permit the jury to find that they were members of the conspiracy alleged in the indictment. Acosta contends that the evidence showed that there existed not the single California- New York conspiracy alleged, but rather multiple conspiracies, and that he was a member only of the smaller and independent conspiracy that operated in New York. Chavez contends that the evidence failed to show that he had any connection with the conspiracy that operated in New York; he also challenges the sufficiency of the evidence to show that the gun seized from his apartment (a) was possessed by him, and (b) was possessed in furtherance of the drug-trafficking conspiracy.
In challenging the sufficiency of the evidence to support a conviction, a defendant bears a heavy burden. See, e.g., United States v. Quattrone, 441 F.3d 153, 169 (2d Cir.2006); United States v. Matthews, 20 F.3d 538, 548 (2d Cir.1994). In considering such a challenge, we must view the evidence in the light most favorable to the government, crediting every inference that could have been drawn in the government's favor, see, e.g., United States v. Locascio, 6 F.3d 924, 944 (2d Cir.1993), cert. denied, 511 U.S. 1070, 114 S.Ct. 1645, 128 L.Ed.2d 365 (1994), and "defer[ring] to the jury's assessment of witness credibility," United States v. Bala, 236 F.3d 87, 93 (2d Cir.2000), and its assessment of the weight of the evidence, see, e.g., United States v. Morrison, 153 F.3d 34, 49 (2d Cir.1998). The conviction must be upheld if " any rational trier of fact could have found the essential elements of the crime beyond a reasonable doubt." Jackson v. Virginia, 443 U.S. 307, 319, 99 S.Ct. 2781, 61 L.Ed.2d 560 (1979) (emphasis in original); see, e.g., United States v. Velasquez, 271 F.3d 364, 370 (2d Cir.2001) (a conviction may be overturned on the basis of insufficiency of the evidence only if, on the evidence viewed in the light most favorable to the government, with all inferences drawn and credibility assessments made in its favor, " `no rational trier of fact could have found the essential elements of the crime charged beyond a reasonable doubt' " (quoting United States v. McDermott, 245 F.3d 133, 137 (2d Cir.2001))). These principles apply whether the evidence being reviewed is direct or circumstantial. See, e.g., Glasser v. United States, 315 U.S. 60, 80, 62 S.Ct. 457, 86 L.Ed. 680 (1942).
In order to convict a defendant of conspiracy, the government must prove both the existence of the conspiracy alleged and the defendant's membership in it beyond a reasonable doubt. See, e.g., United States v. Huezo, 546 F.3d 174, 180 (2d Cir.2008). The essence of any conspiracy is, of course, agreement, and in order to establish a conspiracy, the government must show that two or more persons entered into a joint enterprise with consciousness of its general nature and extent. See, e.g., United States v. Alessi, 638 F.2d 466, 473 (2d Cir.1980). To establish a particular defendant's membership in the alleged conspiracy, the government must present "proof of [his] purposeful behavior aimed at furthering the goals of the conspiracy." United States v. Diaz, 176 F.3d 52, 97 (2d Cir.) (internal quotation marks omitted), cert. denied, 528 U.S. 875, 120 S.Ct. 181, 145 L.Ed.2d 153 (1999). "Both the existence of a conspiracy and a given defendant's participation in it with the requisite knowledge and criminal intent may be established through circumstantial evidence." United States v. Stewart, 485 F.3d 666, 671 (2d Cir.2007). Further,
[t]he government need not show that the defendant knew all of the details of the conspiracy, "so long as he knew its general nature and extent." United States v. Rosa, 17 F.3d 1531, 1543 (2d Cir.1994). Nor [need] the government prove that the defendant knew the identities of all of the other conspirators. United States v. Downing, 297 F.3d 52, 57 (2d Cir.2002).
United States v. Huezo, 546 F.3d at 180; see, e.g., Blumenthal v. United States, 332 U.S. 539, 557, 68 S.Ct. 248, 92 L.Ed. 154 (1947) ("[T]he law rightly gives room for allowing the conviction of those discovered upon showing sufficiently the essential nature of the plan and their connections with it, without requiring evidence of knowledge of all its details or of the participation of others.").
The matter of whether there existed a single conspiracy as charged in the indictment or multiple conspiracies "is a question of fact for a properly instructed jury." United States v. Berger, 224 F.3d 107, 114 (2d Cir.2000) (internal quotation marks omitted).
In order to prove a single conspiracy, the government must show that each alleged member agreed to participate in what he knew to be a collective venture directed toward a common goal. The coconspirators need not have agreed on the details of the conspiracy, so long as they agreed on the essential nature of the plan.
United States v. Geibel, 369 F.3d 682, 689 (2d Cir.) (internal quotation marks omitted), cert. denied, 543 U.S. 999, 125 S.Ct. 619, 160 L.Ed.2d 457 (2004). "[A] single conspiracy is not transformed into multiple conspiracies merely by virtue of the fact that it may involve two or more phases or spheres of operation, so long as there is sufficient proof of mutual dependence and assistance." Id. (internal quotation marks omitted). Thus,
[i]n the context of narcotics operations, ... we have held that even where there are multiple groups within an alleged conspiracy, a single conspiracy exists where the groups share a common goal and depend upon and assist each other, and we can reasonably infer that each actor was aware of his part in a larger organization where others performed similar roles.
United States v. Berger, 224 F.3d at 115 (internal quotation marks omitted); see also United States v. Sureff, 15 F.3d 225, 230 (2d Cir.1994) ("A single conspiracy may encompass members who neither know one another's identities, ... nor specifically know of one another's involvement....").
Here, the district court properly instructed the jury on single versus multiple conspiracies-defendants do not contend otherwise-and we conclude that there was sufficient evidence for the jury to conclude that the single conspiracy alleged in the indictment, operating in California and New York, existed and that both Chavez and Acosta were members of it. Taken in the light most favorable to the government, the evidence included proof of the following.
1. Defendants' Membership in the Conspiracy
Chavez, who operated primarily out of California, supervised the organization's operations in the United States; Chavez reported to his uncle Santiago Chavez-Ayon, known as "Santi," who was based in Mexico. The organization's operations in New York were overseen by Gregorio Barraza ("Barraza"). Some of the narcotics sold by the organization came from Mexico; some came from suppliers in the eastern United States, including Acosta.
Ibarra testified that, prior to moving to New York, he had been friendly with the Barraza brothers when he and they lived in Compton, California ( see Trial Transcript ("Tr.") at 382), and he had met Chavez casually in California ( see id. at 417-18). Ibarra began working with Barraza in New York City in the spring of 2002, engaging in drug trafficking with Barraza, Acosta, and "a lot of [other] people" ( id. at 368). Barraza was in charge of the New York group; Ibarra understood that Barraza's boss was Chavez. ( Id. at 368-69.) Indeed, at one point, when Barraza discovered that several kilograms of cocaine were missing and suspected that Ibarra, high on cocaine and marijuana, had misdelivered them, Barraza said that if Chavez saw Ibarra "all drugged up" Chavez would fire Ibarra. ( Id. at 424-25.)
Under the direction of Barraza, Ibarra began living in a stash house maintained by the organization in Queens, New York. Ibarra's jobs included picking up cocaine from suppliers, delivering it to the organization's distributors, and keeping count of the drug money stored in the stash house.
Acosta supplied the organization with wholesale quantities of cocaine. For example, one of Ibarra's early tasks in New York was to drive in tandem with Barraza to Acosta's house in the Bronx, New York, where Acosta and Barraza gave Ibarra a duffel bag containing 50 kilograms of cocaine. Ibarra temporarily stored the cocaine at the stash house, and over the next few days he delivered bulk quantities to the organization's distributors. Some days thereafter, Ibarra collected sales proceeds from the distributors and delivered money to Acosta. The proceeds of these sales amounted to "more than several hundred thousand dollars." (Tr. 401-02.)
This process was repeated several times, with various quantities of cocaine ( see generally Part II.C.1. below) supplied by Acosta. In addition, on at least one occasion, Ibarra picked up 40 kilograms of cocaine from a supplier other than Acosta, using a vehicle provided by Acosta.
While working with Barraza in New York, Ibarra fielded numerous telephone calls for Barraza from Chavez in California. The government, which conducted court-authorized wiretaps on Chavez's telephone in California, Barraza's telephone in New York, and Ibarra's cell phone, introduced many recordings and transcripts of telephone conversations between Chavez and Barraza in which Chavez gave instructions for or expressed concern over, inter alia, the New York operation's inventory and security.
For example, in early August 2002, concerned that the organization's assets had been depleted, Chavez called Barraza and asked whether Barraza could "put anything together right now" (August 8, 2002 call, GX 15T, at 2). Barraza replied that he had seven kilograms of cocaine; Chavez instructed him ...