Jeffrey Harris pleaded guilty to one count of conspiracy to possess with intent to distribute cocaine and cocaine base, 21 U.S.C. §§ 846, 841(a)(1), and the district court adjusted his base offense level upward two levels pursuant to U.S.S.G. § 2Dl.l(b)(l) for possessing a firearm during the course of his offense. Harris appeals, arguing that the district court should not have applied § 2D1.1(b)(1) because he never personally or constructively possessed a firearm, and played a relatively small role in the conspiracy, and that the district court should have adjusted his offense level downward two levels under the “safety valve” provision, U.S.S.G. § 5C1.2 and U.S.S.G. § 2Dl.l(b)(6). We affirm.
I.
From October 1993 to mid-1996, Harris “worked the table” — he cooked, cut up, and packaged kilogram quantities of crack cocaine into smaller portions for distribution — as part of a large narcotics distribution ring in Illinois and Indiana. He initially worked the table at a drug house on the south side of Chicago managed by Kirk Reynolds, one of the primary conspirators. In early 1995, Harris followed the operation to Indianapolis, and worked the table at two drug houses that were equipped with sophisticated hidden compartments containing large caches of firearms. He was continuously in the presence of co-conspirators who routinely and openly carried firearms, and once while he was present at one of the Indianapolis houses several co-conspirators exchanged gunfire with other individuals. Harris also once helped deliver a large quantity of cocaine from California, delivered large quantities of cocaine to buyers and other drug houses, occasionally collected drug sales proceeds from street dealers, and was responsible for distributing cloned cellular telephones to members of the operation. His involvement in the conspiracy ceased in 1996 when he moved away from Indianapolis.
A federal grand jury indicted Harris along with 13 other members of the operation in May 1997. Harris was charged only with one count of conspiracy to possess with intent to distribute cocaine and cocaine base, and agreed to plead guilty to the charge in May 1998. In the written plea agreement, Harris and the government stipulated that his base offense level was 38 under U.S.S.G. § 2D1.1 (a), and that he should receive a three-level downward adjustment for acceptance of responsibility under U.S.S.G. § 3E1.1. But the parties could not agree whether Harris possessed a firearm in connection with the offense under U.S.S.G. § 2Dl.l(b)(l), and included the following stipulation in the plea agreement:
[I]f the Court determines that the defendant did not possess a firearm in connection with the offense, the parties agree that Harris meets the remaining requirements of U.S.S.G. § 5C1.2. In the event that the defendant meets said requirements, he would be entitled to a two level reduction, pursuant to U.S.S.G. § 2Dl.l(b)(4).1
At sentencing, the district court adopted the findings in the Presentence Investigation Report (PSR), which recommended the upward adjustment, and found that Harris “possessed” firearms within the meaning of § 2D1.1(b)(1) because he regularly worked in a place where firearms were present, had access to the hidden storage compartments in the Indianapolis drug houses, and was continuously surrounded by co-conspirators who openly possessed and used firearms. The court reasoned that the presence of firearms was foreseeable to Harris. With no further oral or written objections to the PSR, the *1057district court imposed a 240-month sentence.
II.
Section 2Dl.l(b)(l) requires a two-level upward adjustment if “a dangerous weapon (including a firearm) was possessed.” U.S.S.G. § 2Dl.l(b)(l); United States v. Zehm, 217 F.3d 506, 516 (7th Cir.2000). This specific offense characteristic applies if weapons were present, unless it is “clearly improbable” that they were connected to the offense. U.S.S.G. § 2D1.1, comment, (n. 3); Zehm, 217 F.3d at 516; United States v. Taylor, 111 F.3d 56, 59 (7th Cir.1997). The government bears the initial burden of establishing by a preponderance of the evidence that the defendant possessed a firearm, but the burden then shifts to the defendant to prove that it was clearly improbable that the weapon was used in connection with the underlying offense. United States v. Berkey, 161 F.3d 1099, 1102 (7th Cir.1998). A defendant “possesses” firearms under § 2D1.1(b)(1) if he actually or constructively possessed a gun, Zehm, 217 F.3d at 516; United States v. Griffin, 150 F.3d 778, 786 (7th Cir.1998); United States v. Wetwattana, 94 F.3d 280, 283 (7th Cir.1996), or if coconspirators possessed firearms in furtherance of jointly undertaken criminal activity so long as their possession was reasonably foreseeable to the defendant, U.S.S.G. § 1B1.3(a)(1)(B) & comment, (n. 2); United States v. Brack, 188 F.3d 748, 763-64 (7th Cir.1999); United States v. Washington, 184 F.3d 653, 659 (7th Cir.1999); Taylor, 111 F.3d at 59. We review the district court’s conclusion that Harris possessed a gun under § 2D1.1(b)(1) for clear error. See Zehm, 217 F.3d at 516.
In disputing application of § 2D1.1(b)(1), Harris argues that he did not actually or constructively possess a weapon. Although he concedes that firearms were present in the drug houses where he worked the table, he contends that the presence of the weapons proves only mere proximity, not constructive possession. The government conceded that Harris never personally carried a gun, but asserts that Harris had constructive possession of the firearms carried by his co-conspirators, or those discovered in the drug houses. The government points out that Harris was an intimate member of a conspiracy whose members engaged in “firearm activity,” was present during a gun battle, was constantly in the presence of co-conspirators carrying weapons, had ready access to the weapons caches, and delivered large quantities of drugs to locations where armed individuals had been hired for security. There is no question that firearms were present during this offense, but to show constructive possession the government had to prove that Harris demonstrated ownership, dominion, authority, or control of at least one of the caches of weapons, see id.) United States v. Richardson, 208 F.3d 626, 632 (7th Cir.2000), and the only suggestion in this record that Harris exercised such possession comes entirely from the mouth of the government’s attorney. Statements of counsel are not evidence, see United States v. Fetlow, 21 F.3d 243, 248 (8th Cir.1994), and our reading of the PSR and the indictment, along with the testimony from Harris’s change-of-plea hearing, reveals nothing but Harris’s proximity to the firearms, which is insufficient to constitute constructive possession, see United States v. Windom, 19 F.3d 1190, 1200-01 (7th Cir.1994).
But a defendant can also possess a firearm for purposes of § 2Dl.l(b)(l) under co-conspirator liability principles, see Brack, 188 F.3d at 763-64; Berkey, 161 F.3d at 1102, and the district court’s application of § 2D1.1(b)(1) under such a theory is supported by the record. The district court adopted the findings of fact in the PSR, which references information contained in the indictment. Count 1 charged Harris with the same drug-distribution conspiracy as all of his co-defendants. Counts 15-19 charged co-conspirators Morris Carr, Terrell Carter, and Michael Harris with various substantive weapons offenses, and Michael Harris was convicted of both Count 1 and the *1058weapons charges.2 Additionally, the PSR recounts numerous instances in which firearms were possessed by coconspirators James Anthony, Toymiko Bradley, Morris Carr, Terrell Carter, Michael Harris, and Kirk Reynolds, all of whom pleaded guilty to, or were convicted under, Count 1 of the indictment. Harris asserts, however, that his involvement in the charged conspiracy was significantly less than that of his co-conspirators, and when queried on this point at oral argument, stated that he was involved only in a “conspiracy to work the table,” and that he simply did not participate in the more serious criminal activity of his co-conspirators. It is well-settled, however, that a participant in joint criminal activity can be liable for the foreseeable criminal acts of another in furtherance of the joint criminal activity. See Pinkerton v. United States, 328 U.S. 640, 646-48, 66 S.Ct. 1180, 90 L.Ed. 1489 (1946); see also United States v. Missick, 875 F.2d 1294, 1301-02 (7th Cir.1989) (co-conspirators may be subject to enhanced sentences under Pinkerton liability theory). Furthermore, Harris made no written or verbal objections to the factual findings contained in or incorporated by reference into the PSR — findings that establish that Harris did more than merely work the table' — and cannot now challenge those facts on appeal. See United States v. Staples, 202 F.3d 992, 995 (7th Cir.2000). The district court did not clearly err in finding that Harris possessed firearms during the offense for purposes of § 2D1.1(b)(1).
Harris next contends that he merited a two-level downward adjustment under the “safety valve” provision, U.S.S.G. § 5C1.2. Under this section and § 2D1.1(b)(6), sentencing courts can adjust an offense level of 26 or greater downward two levels if the defendant can demonstrate that (1) he is a first time offender; (2) he did not possess or use a firearm in connection with the offense; (3) the offense did not result in death or serious bodily injury to any person; (4) he was not an organizer or leader of the criminal activity; and (5) he made a good faith effort to cooperate with the government. See 18 U.S.C. § 3553(f); U.S.S.G. § 5C1.2. Whether co-conspirator liability is a basis for determining possession of a firearm under § 5C1.2 is an issue that we have never addressed, but the majority of circuits to reach the issue have ruled that it is not.3 Harris, however, did not raise this issue or object to the district court’s failure to apply § 5C1.2 and § 2D1.1 (b)(6) at sentencing. He acknowledges in his brief that he may have failed to preserve this issue for appeal, but argues that we should determine otherwise and reach the merits of his argument, or that we should review the district court’s failure to apply § 5C1.2 for plain error. The government believes that Harris forfeited the issue and that we may review it for plain error, but contends that the district court did not commit plain error. Harris failed to preserve this issue for appeal, but we believe that he waived, rather than forfeited, the argument, and therefore we cannot reach its merits.
Waiver and forfeiture are related doctrines; waiver occurs when a defendant intentionally relinquishes or abandons a know right, whereas forfeiture occurs when a defendant fails to timely assert his rights. Staples, 202 F.3d at 998 (citing United States v. Olano, 507 U.S. 725, 730-34, 113 S.Ct. 1770, 123 L.Ed.2d 508 (1993)). We review forfeited issues for plain error, see id., but we cannot review waived issues at all because a valid waiver *1059leaves no error for us to correct on appeal, United States v. Davis, 121 F.3d 335, 337-38 (7th Cir.1997). Here, the parties stipulated that Harris would be eligible for safety valve relief if the district court determined that he did not possess a firearm in the course of the offense. But the district court concluded otherwise, the Sentencing Guidelines recommendations in the PSR made no mention of § 5C1.2 or § 2D1.1(b)(6), and, when queried by the district court, both Harris and trial counsel affirmatively stated that they had no objections to the PSR apart from the § 2Dl.l(b)(l) firearm possession adjustment. Thus, despite having raised the § 5C1.2 question during plea negotiations, Harris extinguished the issue by affirmatively declining to object at sentencing. See id.; United States v. Redding, 104 F.3d 96, 99 (7th Cir.1996).
Finally, Harris asserts that his trial attorney was constitutionally ineffective by failing to argue for a downward adjustment under § 5C1.2 and § 2Dl.l(b)(6). To prevail, he must demonstrate that counsel’s performance fell below an objective standard of reasonableness and that counsel’s errors were prejudicial. Strickland v. Washington, 466 U.S. 668, 687, 104 S.Ct. 2052, 80 L.Ed.2d 674 (1984). The availability of safety valve relief for defendants such as Harris is an open question in this circuit, and it was possible that Harris’s offense level could have been lowered by two had trial counsel raised the issue at sentencing. But we have generally discouraged ineffective assistance of counsel claims on direct appeal because we presume counsel’s performance to fall within a wide range of reasonable professional assistance and our inquiry is necessarily limited to the facts in the trial record. See United States v. Godwin, 202 F.3d 969, 973 (7th Cir.2000). Trial records are typically not sufficiently developed for us to conclude whether counsel’s performance was deficient, United States v. Johnson-Wilder, 29 F.3d 1100, 1104 (7th Cir.1994), and this case is no exception: on this record we cannot say that counsel’s failure to request a downward adjustment under the safety valve was not a strategic decision. Counsel argued for the minimum sentence within the guideline range rather than asserting that the district court should have applied the safety valve provision, which may or may not have applied to Harris, and counsel was entitled to be selective, especially where the pursuit of other avenues may have risked opening the door to 'the inclusion of unfavorable facts in the record. See United States v. Davenport, 986 F.2d 1047, 1050 (7th Cir.1993).
Accordingly, we Affirm Jeffrey Harris’s sentence.
. Section 2D 1.1 (b)(4) was later renumbered § 2D1.1(b)(6). See U.S.S.G. App. C, amendment 555 (Nov. 1997).
. We recently affirmed Michael Harris’s convictions in United States v. Thornton, 197 F.3d 241 (7th Cir.1999).
. See United States v. Clavijo, 165 F.3d 1341, 1343 (11th Cir.1999); United States v. Wilson, 114 F.3d 429, 432 (4th Cir.1997); In re Sealed Case, 105 F.3d 1460, 1462-63 (D.C.Cir.1997); United States v. Wilson, 105 F.3d 219, 222 (5th Cir.1997); but see United States v. Hallum, 103 F.3d 87, 89-90 (10th Cir.1996) (participants in joint criminal activity can be held responsible for the foreseeable possession of firearms in furtherance of the conspiracy by other participants for purposes of § 5C1.2).