SILER, Circuit Judge.

Defendant Ricky Lee Newton appeals his conviction and sentence for conspiracy to possess with intent to distribute 100 to 1000 kilograms of marijuana in violation of 21 U.S.C. § 846. He raises questions concerning searches, competency at trial, and sentence computation. For reasons stated hereafter, the conviction and sentence are AFFIRMED.

BACKGROUND

On January 10, 2002, state police stopped Eduardo Romero in Missouri driving a truck with a false compartment containing marijuana. Romero confessed that he had made nineteen previous marijuana deliveries from Texas to Michigan to a man named "Rick," whom Romero identified later as Newton. Romero gave details of his prior trips that were corroborated later by motel ledgers, phone records and his truck odometer. He also identified the location where he unloaded the marijuana at a rural residence of a man named "Tim," later identified as Tim Wilson, who helped unload the marijuana. Romero agreed to cooperate in a controlled delivery of the marijuana.

Upon arrival in Michigan, the delivery on January 11, 2002 occurred exactly as Romero indicated it would. Romero arrived at Wilson's barn where Wilson began unloading the marijuana from Romero's truck and placing it into black plastic garbage bags. Newton arrived later and backed the truck he was driving into the barn where Wilson and Newton then began loading the marijuana into Newton's truck. Upon Romero's signal, officers descended on the scene, seizing 33 bundles of marijuana from Newton's truck and two stored in the rafters of the barn.

Upon arrest, Newton was found with two insurance receipts listing 6220 Fort Street, Birch Run, Bridgeport Township, Michigan as his address, which he had also given to his probation officer as his address. An additional receipt for building supplies dated January 4, 2002 was found in the glove box of the truck Newton was driving. It listed 8205 East Dodge Road, Forest Township, Michigan as his address. A receipt dated January 11, 2002 for building supplies made out to his fiancee, Lori Cool, was also found on Newton listing the same Dodge Road address. Newton informed officers that he resided at 9439 East Vienna Road, Forest Township, Michigan, which was determined by public records to be owned by Newton's father. Finally, the truck Newton was driving was registered to Cool, at an address of 2307 Vassar Road.

After a public records search, Sergeant Terence Green submitted an affidavit to a state judge for a search warrant for all four addresses. Included in the affidavit was information from a previously reliable informant stating a belief that Newton was engaged in drug dealing. However, the informant provided no facts in regard to drug dealing, but generally stated a series of beliefs. The judge granted the warrant on January 16, 2002. However, while executing the warrant, the Dodge Road address was identified as a house under construction. A marijuana package identical to those recovered from Romero's truck was found in an outbuilding at this address. Additionally, the Vassar Road address turned out to be a rental property with no connection to Newton's criminal activities.

Newton was indicted for substantive drug offenses and conspiracy with Wilson, and both known and unknown parties, to possess with intent to distribute 1000 kilograms or more of marijuana in violation of 21 U.S.C. § 846. Before trial, Newton moved to suppress evidence seized from the addresses as derived from an affidavit made with reckless disregard for the truth and lacking any information linking the addresses to criminal activity. He specifically pointed to the informant's non-factual conclusions and Sergeant Green's perceived lack of due diligence in not making more effort to verify the status of the house under construction and the rental unit. The government did not defend much of the information in the affidavit, but argued that when stripped of questionable material, the affidavit still contained probable cause to search the four addresses. The district court agreed as to all the addresses except for Vassar Road. In relation to that address, the district court found insufficient information had been presented to support a search. However, the court upheld the search as being based on the police's good faith reliance on the warrant.

Wilson and Newton were tried separately. Before Newton's trial, Wilson was acquitted of conspiracy, and the substantive charges against Newton were dismissed. Throughout Newton's trial, the government's main contention was the evidence supported a conspiracy between Newton and Wilson.

At the beginning of the second trial day, Newton's counsel complained to the court that Newton had not been able to sleep for three days due to being in a small holding cell with sixty other people, was not allowed to shower and was being denied basic hygiene. Counsel requested the court aid in securing at least "basic accommodations." The Deputy U.S. Marshal was directed to look into the matter. At the beginning of the third day of trial, Newton's counsel again complained to the court that Newton was not being allowed to sleep due to the conditions in the holding cell. Counsel also informed the court that "the difficulty with — with Mr. Newton being sleep deprived, he's constantly babbling during the course of the trial. I'm trying to tell him to keep quiet, unfortunately he's not making any sense. I think — I think the jailer can do something to at least allow him to sleep." The court again directed the Deputy U.S. Marshal to address the matter. The issue was not brought up again during trial and appears to have been satisfactorily corrected.

During closing arguments, the defense prominently referred to an audio tape that had been made of Newton's conversations with Romero while unloading the truck. A government agent had testified that the tape did not pick up any identifiable conversation and was just static. The defense asked the jury to consider that the government did not play the tape for them, insinuating it was exculpatory and that was the reason why the tape was not played. In rebuttal, the prosecutor argued that if Newton wanted the tape played, he could have played it himself. The defense objected, calling the argument impermissible burden shifting since the defense has no obligation to produce evidence. The objection was overruled. The jury found Newton guilty of conspiring to possess with intent to distribute an amount of 100 kilograms or more of marijuana, but less than 1000 kilograms.

Before trial, the government served enhancement notice of two prior felony drug convictions under 21 U.S.C. § 851. Based upon these convictions, Newton was classified, over his objection, as a career offender under USSG § 4B1.1, with a guideline range of 360 months to life imprisonment. The court sentenced Newton to 360 months.

Newton appeals issues concerning: 1) the denial of his suppression motion; 2) the sufficiency of the evidence supporting his conviction; 3) whether a competency hearing was required due to sleep deprivation; 4) prosecutorial misconduct; and 5) whether his career offender status is a factual issue that must be submitted to a jury.

ANALYSIS

A. Fourth Amendment seizure-insufficiency of the affidavit

Newton claims the court erred in denying his motion to suppress. In reviewing a suppression motion, we review a court's factual findings for clear error, while conclusions of law are reviewed de novo. United States v. Helton, 314 F.3d 812, 820 (6th Cir. 2003). However, great deference is given a judge's decision to issue a warrant, which should only be set aside if it is found to have been "arbitrary." Id.

Newton contends, and the government stipulated, that much of the information contained in the affidavit was speculation, which the district court took into account during its review. If sufficient cause remains in an affidavit after being stripped of false or unwarranted information, the warrant may still be upheld. United States v. Ursery, 109 F.3d 1129, 1132-33 (6th Cir. 1997).

The judge had strong reason to suspect that Newton was a drug dealer with continuing and ongoing operations based on the detailed information supplied by Romero. "[I]n the case of drug dealers, evidence is likely to be found where the dealers live." United States v. Jones, 159 F.3d 969, 975 (6th Cir. 1998) (internal citations omitted). Additionally, with continuing criminal operations, any issue of staleness, or the lack of a direct known link between the criminal activity and residence, becomes minimal. See United States v. Greene, 250 F.3d 471, 481 (6th Cir. 2001).

Based on evidence obtained upon Newton's arrest, the police had cause to suspect that Newton maintained residences at three different locales, which was relayed to the judge in the supporting affidavit: 6220 Fort Street due to the insurance receipts and the information provided to his probation officer; 9439 East Vienna Road due to Newton's statement to police corroborated by public records that Newton's father owned the property; and 8205 East Dodge Road based on the receipts for building supplies listing Newton's residence at that address, which also corroborated information from the informant that Newton was moving into a house he was building.

Given that probable cause generally exists to search for the fruits and instrumentalities of criminal activity at the residence of a drug dealer with continual and ongoing operations, the judge's decisions as to these locales cannot be said to have been arbitrary. Detailed evidence of Newton's operations was provided to the judge. The police then supplied him with evidence that these addresses were locations where Newton was maintaining a residence. Without regard to any other information in the affidavit, probable cause existed to issue the warrant in relation to these three presumed residences of Newton.

B. Sufficiency of the evidence-conspiracy

Newton claims sufficient evidence of co-conspirators, particularly in light of Wilson's acquittal and Romero's cooperating witness status, was not produced at trial. Newton claims the rule of consistency, which requires the acquittal of a sole remaining conspirator if all co-conspirators are acquitted, and the fact that he cannot be convicted for conspiring with a government agent, should require his acquittal. For Newton to prevail, a sufficiency of the evidence review must establish that, when viewing the evidence in the light most favorable to the government, no rational trier of fact could have found beyond a reasonable doubt in favor of the government. See United States v. Davis, 177 F.3d 552, 558 (6th Cir. 1999).

1. Wilson's acquittal. First, the rule of consistency has no continuing validity. See United States v. Crayton, 357 F.3d 560, 566-67 (6th Cir. 2004). Second, the rule was not applied if co-conspirators were separately tried. United States v. Sachs, 801 F.2d 839, 845 (6th Cir. 1986). Therefore, Newton can be convicted of conspiring with Wilson despite Wilson's acquittal.

2. Romero as a conspiring government agent. Romero's testimony provided evidence of an agreement not only between himself and Newton, but among Wilson, Newton and unknown Texas suppliers. Sufficient evidence was adduced of a conspiracy between Newton and the unnamed/unknown co-conspirators that the indictment referred to, which can sustain a conspiracy. See United States v. Anderson, 76 F.3d 685, 688-89 (6th Cir. 1996). Hence, the rule from United States v. Pennell, 737 F.2d 521, 536 (6th Cir. 1984), that proof of an agreement between a government agent and the defendant cannot form the basis of a conspiracy, is inapplicable. Besides, Romero was not a government agent except on the final delivery.

C. Competency for trial

Newton claims he was incompetent during trial due to being sleep deprived while being detained for trial. Newton contends that the trial judge should have ordered a competency hearing sua sponte on the basis of Newton's counsel informing the court on the third day of trial that "the difficulty with — Mr. Newton being sleep deprived, he's constantly babbling during the course of the trial. I'm trying to tell him to keep quiet, unfortunately he's not making any sense."

A court's failure to order a competency hearing sua sponte is reviewed for "[w]hether a reasonable judge, situated as was the trial court judge whose failure to conduct an evidentiary hearing is being reviewed, should have experienced doubt with respect to competency to stand trial." Williams v. Bordenkircher, 696 F.2d 464, 467 (6th Cir. 1983) (internal citations omitted).

"It has long been accepted that a person whose mental condition is such that he lacks the capacity . . . to consult with counsel, and to assist in preparing his defense may not be subjected to a trial." Drope v. Missouri, 420 U.S. 162, 171, 95 S.Ct. 896, 43 L.Ed.2d 103 (1975). The test is "whether a criminal defendant 'has sufficient present ability to consult with his lawyer with a reasonable degree of rational understanding — and whether he has a rational as well as factual understanding of the proceedings against him.'" Id. at 172, 95 S.Ct. 896 (quoting Dusky v. United States, 362 U.S. 402, 80 S.Ct. 788, 4 L.Ed.2d 824 (1960) (per curiam)). "It is a violation of due process to convict a person who lacks such competence at the time of trial." Pate v. Smith, 637 F.2d 1068, 1071 (6th Cir. 1981).

While "a trial court must always be alert to circumstances suggesting a change that would render the accused unable to meet the standards of competence to stand trial," Drope, 420 U.S. at 181, 95 S.Ct. 896, Newton fails to point to evidence in the record that would have put the court on notice that a competency issue had arisen. At most, the trial court was made aware that Newton was lacking sleep, which was having some impact on his behavior at trial. Newton's counsel asked for, and evidently received, relief from the court. Counsel did not request a continuance to cure the sleep issue. This fact alone suggests that the sleep deprivation issue had not risen to the level of a due process violation since, at worst, Newton's competency issue was a temporary one that was curable by sleep, unlike the more familiar incompetency issues associated with mental illness. As counsel did not request a continuance, the trial court reasonably would not perceive any competency issue. Defense counsel was not indicating that Newton's ability to comprehend the proceedings or mount a defense was being impacted to such an extent that a "cure" was required.

Multiple factors "are all relevant in determining whether further inquiry is required, but . . . even one of these factors standing alone may, in some circumstances, be sufficient. There are, of course, no fixed or immutable signs which invariably indicate the need for further inquiry to determine fitness to proceed." Drope, 420 U.S. at 180, 95 S.Ct. 896. The record is devoid of any evidence of Newton's falling asleep or any other signs that his sleep deprivation had risen to the level of a constitutional due process violation. The trial court had multiple factors within its sensory perceptions to rely upon in evaluating the situation and Newton's competency. Without more within the record, this court declines to find that the trial court, situated as it was, should have experienced doubt with respect to Newton's competency to stand trial.

D. Prosecutorial misconduct

Newton claims the prosecutor improperly shifted the burden during closing argument by arguing to the jury that Newton could have played an audiotape that the government chose not to play for the jury. Improper burden shifting is a violation of due process that is reviewed de novo. United States v. Clark, 982 F.2d 965, 968 (6th Cir. 1993).

The argument at issue was made to rebut defense insinuations that the government intentionally kept evidence away from the jury. Clark dealt with a similar situation where the defense implied at closing that the government failed to call a witness because the evidence would be favorable to the defendant. 982 F.2d at 968. The prosecutor argued in rebuttal that the defense could have called the witness if desired. Id. at 968-69. As in Clark, it is evident that Newton's prosecutor did not shift the burden, but made a legitimate reply to defense assertions that the government hid evidence from the jury. The defense opened the door to this rebuttal.

E. Evidentiary sufficiency-failure to amend the indictment

Newton claims the evidence of the quantity of marijuana was insufficient to sentence him under the enhanced penalty provision of 21 U.S.C. § 841(b)(1)(B)(vii) (100 kilograms or more of marijuana). In his reply brief, Newton also claims the indictment was constructively amended during sentencing in violation of the Sixth Amendment, since he was indicted under 21 U.S.C. § 841(b)(1)(A) for possessing 1000 kilograms or more of marijuana, but the jury ultimately convicted him for possessing between 100 to 1000 kilograms, which sentence is under 21 U.S.C. § 841(b)(1)(B). Newton claims these differing amounts are separate statutory crimes so he should have been indicted for the lesser quantity for which he was actually convicted.

A sufficiency of the evidence review must establish that, when viewing the evidence in the light most favorable to the government, no rational trier of fact could have found beyond a reasonable doubt in favor of the government. Davis, 177 F.3d at 558. As Newton raises the constructive amendment issue for the first time, it is reviewed for plain error. United States v. Taylor, 102 F.3d 767, 769 (6th Cir. 1996).

1. Sufficiency of the evidence. Newton argues that only an "official" weighing could establish an amount beyond a reasonable doubt. However, the government provided logically extrapolated amounts based on the number of packages (35) seized from Romero and an "official" weighing of one of those packages, minus its packaging (23.6 pounds). Romero then testified as to the number of trips he made to Newton delivering "full loads," which he testified were identical to the amount seized when he was apprehended, along with some additional "light" loads.

The government contends, based on the amount seized and the number of loads testified to being delivered, that an amount of 2720 pounds (1236 kilograms) was proved at trial. However, the jury returned a verdict for an amount between 100 kilograms and 1000 kilograms, which is consistent with the approximately 175 pounds (80 kilograms) that was actually seized, with an allowance added for the extra delivered loads. These additional deliveries would, without doubt, amount to more than an extra 20 kilograms if Romero's testimony is to be believed. The jury concluded the evidence did not support a conviction for more than 1000 kilograms, but that it did for between 100 and 1000 kilograms. The evidence supports the jury's decision.

2. Constructive amendment. The claim that the indictment was constructively amended is without merit as the conviction for the smaller amount is a lesser-included offense of the indicted offense. See United States v. Solorio, 337 F.3d 580, 589-91 (6th Cir. 2003).

F. Career offender status adjudged in violation of due process

Newton argues that his career offender status under USSG § 4B1.1 is a factual issue that must be submitted to a jury under the Fifth and Sixth Amendments to the Constitution. Constitutional challenges to a sentence are reviewed de novo. United States v. Perez-Olalde, 328 F.3d 222, 224 (6th Cir. 2003).

The statutory maximum for Newton's crime is 40 years. 21 U.S.C. § 841(b)(1)(B). One prior felony drug conviction raises the prescribed sentence to not less than 10 years and not more than life imprisonment. Id. Therefore, the constitutional issues addressed in Apprendi v. New Jersey, 530 U.S. 466, 120 S.Ct. 2348, 147 L.Ed.2d 435 (2000), have no applicability, as prior convictions may be used as facts that increase prescribed sentences without being submitted to a jury. See Harris v. United States, 536 U.S. 545, 562-64, 122 S.Ct. 2406, 153 L.Ed.2d 524 (2002). It was Newton's prior convictions which determined his career offender status and sentencing range, not any factual issues that must be proved beyond a reasonable doubt.

AFFIRMED.