OPINION OF THE COURT
John Johnson appeals his judgment of conviction and sentence following a jury trial. Although he raises four assignments of error, Johnson’s most significant claim is that the District Court’s individual voir dire procedure violated his constitutional rights and the Federal Rules of Criminal Procedure. Because we are persuaded by neither Johnson’s principal argument nor his ancillary claims, we will affirm the judgment and sentence of the District Court.
I
On February 3, 2007, police officers from Cheltenham Township, Pennsylvania, enlisted a confidential informant to arrange a controlled purchase of cocaine from his usual supplier, who was later identified as John Johnson. That evening, Officer Tom Fahy and the confidential informant purchased a bag of cocaine from Johnson in the parking lot of’ a Home Depot. Six days later, the informant arranged a controlled purchase in Philadelphia, where officers arrested Johnson as he approached the informant’s car. A search of Johnson’s person yielded $200, a loaded semi-automatic handgun, two bags of white powder, and a cell phone associated with the phone number that the informant had called to arrange the buys. Laboratory testing later confirmed that the substances recovered during both buys amounted to 8.76 grams of cocaine.
Johnson was tried before a jury and convicted of cocaine distribution and possession of cocaine with intent to distribute in violation of 21 U.S.C. § 841(a)(1) and (b)(1)(C) (Counts One and Two), using and *141 carrying a firearm during a drug-trafficking offense in violation of 18 U.S.C. § 924(c)(1) (Count Three), and possession of a firearm by a convicted felon in violation of 18 U.S.C. § 922(g)(1) (Count Four). Johnson was later sentenced to 120 months’ imprisonment, six years of supervised release, a $1000 fine, and a $400 special assessment.
Johnson raises four issues on appeal, claiming: (1) the District Court violated his constitutional rights and Federal Rule of Criminal Procedure 43 by questioning prospective jurors at sidebar outside his presence, (2) the Court abused its discretion in denying his motion to disclose the identity of the confidential informant, (3) the evidence was insufficient to support his conviction on Count Three, and (4) the Court erred by imposing an upward variance. We evaluate each argument in turn. 1
II
During jury selection, the District' Court followed the customary procedure of questioning prospective jurors first in open court and later individually at sidebar. Johnson remained at the defense table during the sidebar proceedings, which were on the record. The District Court ruled on challenges for cause at sidebar, and thereafter counsel returned to their tables to mark their peremptory challenges.
Johnson argues that this procedure violated his constitutional right to be present at all stages of his trial. But neither Johnson nor his counsel objected to the procedure during jury selection, even when prompted to do so by the District Court. The decision not to object to voir dire conducted at sidebar and outside the presence of the defendant is a tactical decision similar to the one at issue in
Gonzalez v. United States,
[a] magistrate judge’s or a district judge’s particular approach to voir dire both in substance — the questions asked — and in tone — formal or informal — may be relevant in light of the attorney’s own approach. The attorney may decide whether to accept the magistrate judge based in part on these factors. As with other tactical decisions, requiring personal, on-the-record approval from the client could necessitate a lengthy explanation the client might not understand at the moment and that might distract from more pressing matters as the attorney seeks to prepare the best defense.
Id.
An attorney’s obligation to consult with his client “does, not require counsel to obtain the defendant’s consent to ‘every tactical decision.’ ”
Florida v. Nixon,
Because no objection was made to the jury selection process, Johnson’s claim of a Rule 43 violation is also waived. Rule 43 requires that a defendant be present at “every trial stage, including jury impanelment.” Fed.R.Crim.P. 43(a). The Supreme Court has held that “failure by a criminal defendant to invoke his right to be present under [Rule 43] at a conference which he knows is taking place between the judge and a juror in chambers constitutes a valid waiver of that right.”
United States v. Gagnon,
Likewise, we have found that “[a] defendant need not be warned expressly of his or her rights under Rule 43, nor must a waiver exist on the record [because] the simple failure to assert the right constitutes a waiver.”
United States v. Bertoli,
Ill
Johnson raises three additional issues. As they are neither difficult to resolve nor *143 of precedential import, we discuss them only briefly.
A
Johnson claims the District Court abused its discretion in denying his motion to disclose the identity of the confidential informant. “We review the District Court’s refusal to order disclosure of [a] confidential informant’s identity for abuse of discretion.”
United States v. Johnson,
Johnson has failed to meet this burden. “The mere speculation that an eyewitness may have some evidence helpful to defendant’s case is not sufficient to show the specific need required by Roviaro.Id. Though the confidential informant was an eyewitness to the two drug transactions, Johnson’s suggestion that his testimony would support a mistaken-identity defense is speculative because Officer Fahy, who was present at both buys, positively identified Johnson, as did the officers who observed Johnson approach the informant’s car on February 9, 2007. Because Johnson did not meet his burden under Roviaro, the District Court was well within its discretion in denying his motion.
B
Johnson’s penultimate argument challenges the sufficiency of the evidence supporting his conviction for possession of a firearm in furtherance of a drug-trafficking offense. When evaluating whether a jury verdict rests on legally sufficient evidence, we apply “a particularly deferential standard of review.”
United States v. Dent,
When evaluating the reasonableness of a jury’s finding that a defendant possessed a gun in furtherance of a drug-trafficking offense, we consider
the type of drug activity that [was] being conducted, accessibility of the firearm, the type of the weapon, whether the weapon [was] stolen, the status of the possession (legitimate or illegal), whether the gun [was] loaded, proximity to drugs or drug profits, and the time and circumstances under which the gun [was] found.
United States v. Sparrow,
C
Finally, Johnson challenges the substantive reasonableness of his sentence. We review this claim for abuse of discretion,
United States v. Doe,
Johnson’s Sentencing Guidelines range was 97 to 106 months, and he received a sentence of 120 months’ imprisonment. The record demonstrates that the District Court carefully reviewed the relevant sentencing factors of 18 U.S.C. § 3553(a). In doing so, the Court noted that Johnson’s prior sentences did not “appear to have captured completely the seriousness of those offenses or the punishment that the Judges in those cases wished to impose upon [him].” The failure of those shorter sentences to deter Johnson, his unwillingness to accept responsibility, and his long history of criminal behavior all support the District Court’s upward variance. Accordingly, we find no abuse of discretion.
IV
For the reasons stated, we will affirm the District Court’s judgment of conviction and sentence.
Notes
. The District Court exercised jurisdiction pursuant to 18 U.S.C. § 3231. We have jurisdiction over this appeal pursuant to 28 U.S.C. § 1291 and 18 U.S.C. § 3742(a).
