Opinion by Judge FISHER; Dissent by Judge O’SCANNLAIN.
FISHER, Circuit Judge:Gregory Sperow appeals his conviction for possession of marijuana with intent to distribute, asserting that the post-indictment delay in his arrest amounted to a violation of his Sixth Amendment right to a speedy trial. Sperow also appeals an enhancement of his sentence, arguing that it was improperly based on a prior conviction not proven to the jury or admitted by the defendant, and that the government did not give him proper notice of its intent to seek such an enhancement. We affirm Sperow’s conviction. However, we agree that the government fatally compromised its notice of a proposed sentence enhancement and therefore vacate Sperow’s sentence and remand for resentencing without the enhancement.
I. Background
Gregory Sperow was indicted in February 1996 on one count of possession of marijuana with intent to distribute, in violation of 21 U.S.C. §§ 841(a)(1) & 846. Sperow was ultimately arrested in California in May 2004, and proceedings on the indictment began in July 2004. The district court denied Sperow’s timely pre-trial motion to dismiss his indictment due to a violation of his Sixth Amendment right to a speedy trial.
On August 12, 2004, the government filed a Notice of Filing of Enhanced Punishment Notice Pursuant to 21 U.S.C. §§ 851 and 841(b)(l)(B)(vii). This notice stated that the government sought an enhanced mandatory minimum sentence “since this offense involves more than 100 kilograms of marihuana and because de*1225fendant has a prior conviction in United States District Court for the Southern District of California.” The government attached a copy of the judgment in Sperow’s previous conviction to the notice. In June 2005, the government determined that the marijuana involved in the offense weighed 98.5 kilograms, not over 100 kilograms as previously asserted. The government therefore filed a motion stating that it “hereby moves to strike the second paragraph of the grand jury indictment, which allegation established an enhanced penalty, on grounds subsequent investigation revealed that the amount of marijuana seized weighed no more than 98.5 kilograms of marijuana.”
During Sperow’s trial, in response to the court’s inquiry about whether the drug amount could “affect any sentencing aspect,” the government referred to its motion to strike and asserted that Sperow was facing a “sentence of no more than 20 years.” On June 22, 2005, a jury found Sperow guilty.
The probation office provided the parties with a presentence report on August 8, 2005. In an addendum, the probation office explained that:
[T]he probation office posed a question to the government specifically asking about the validity of the notice of enhanced penalty after the statute to which it was tied, 21 USC 841(b)(1)(B), was stricken from the Indictment. At that time, the government communicated via email that the enhancement was gone. Based primarily on this assertion by the government and it’s [sic] failure to mention the notice of enhanced penalty at trial, the probation office believe the enhancement was gone....
The probation office later concluded that there had been a “mis-communieation with the government regarding the notice of enhanced penalty” and recalculated its sentence recommendation in line with the government’s “contention that] the notice of enhanced penalty ... is still valid.” During sentencing Sperow argued that the government’s § 851 notice was no longer valid in light of the government’s subsequent motion to strike. The district court rejected this argument, concluding that a “pragmatic reading” and a “common sense interpretation[ ] shows that the Government did not withdraw or otherwise invalidate its notice to seek an enhanced penalty to 21 U.S.C. § 851” based on Sperow’s prior conviction. The district court sentenced Sperow under the penalty provisions of § 841(b)(1)(D) and enhanced Sper-ow’s sentence from five to 10 years based on his prior conviction for a felony drug offense.
II. Sixth Amendment Right to a Speedy Trial
We hold that the delay between Sperow’s indictment in 1996 and his arrest in 2004 did not violate Sperow’s right to a speedy trial. We consider four factors in assessing a defendant’s claim that his Sixth Amendment right to a speedy trial has been violated: (1) the length of the delay; (2) the reason for the delay; (3) the defendant’s assertion of his right; and (4) prejudice to the defendant. See Barker v. Wingo, 407 U.S. 514, 530-32, 92 S.Ct. 2182, 33 L.Ed.2d 101 (1972); United States v. Tanh Huu Lam, 251 F.3d 852, 855 (9th Cir.2001). These are “ ‘related factors and must be considered together with such other circumstances as may be relevant’ ”; none of the four alone is either “ ‘necessary or sufficient’” to finding a Sixth Amendment violation. Tanh Huu Lam, 251 F.3d at 856 (quoting Barker, 407 U.S. at 533, 92 S.Ct. 2182).
The government concedes that the delay between Sperow’s indictment and his arrest was more than sufficient to trigger a speedy trial inquiry. See Barker, 407 U.S. at 530-31, 92 S.Ct. 2182.
*1226The district court found that Sperow deliberately evaded the authorities after being linked to a shipment of marijuana in Oregon, specifically that Sperow “knew he was in trouble and intended to evade justice.” The court further found that the government was reasonably diligent in attempting to locate and arrest Sperow. We review these findings of fact for clear error. See United States v. Beamon, 992 F.2d 1009, 1013 (9th Cir.1993). Neither finding is clearly erroneous. Contrary to government counsel’s exaggerated assertion at oral argument, Sperow did not “vanish[] from the face of the earth.” Sperow used his real name in some business transactions and to pay taxes. Nonetheless, there is sufficient evidence supporting the district court’s finding that Sperow deliberately concealed his whereabouts. Sperow adopted an alias, and an officer investigating other charges against Sperow testified that he informed the defendant’s brother that Sperow was wanted and warned him against harboring a fugitive. Similarly, although Sperow’s use of his real name in some instances cuts against a finding of governmental diligence, there is evidence to support the district court’s finding, including the government’s periodic credit and criminal history checks between 1996 and 2003, and Oregon officials’ practice of sending leads to counterpart agents in California who were also attempting to locate Sperow. Given the findings that Sperow deliberately evaded authorities and the government was reasonably diligent in attempting to locate him, the district court correctly found that Sperow himself was the reason for the delay in his arrest.
Accordingly, the other two Barker factors also cut against Sperow’s Sixth Amendment claim. When a suspect knows the authorities are looking for him and he seeks to avoid them, “Barker*s third factor, concerning invocation of the right to a speedy trial, ... weigh[s] heavily against him.” Doggett v. United States, 505 U.S. 647, 653, 112 S.Ct. 2686, 120 L.Ed.2d 520 (1992). Moreover, because Sperow caused the delay in his arrest, he has to show actual prejudice in order to prevail on Barker's, final factor. See United States v. Manning, 56 F.3d 1188, 1194-95 (9th Cir.1995). Sperow does not assert that he suffered actual prejudice as a result of the delay. In sum, we hold that Sperow’s Sixth Amendment right to a speedy trial was not violated and affirm his conviction.
III. Sentence Enhancement
United States v. Weiland, 420 F.3d 1062, 1079-80 n. 16 (9th Cir.2005), forecloses Sperow’s argument that raising the statutory maximum penalty from five to 10 years under 21 U.S.C. § 841(b)(1)(D) was unconstitutionally based on a prior conviction that had not been established by a jury verdict or his own admission. See also United States v. Torres-Hernandez, 447 F.3d 699, 706 (9th Cir.2006).
However, we agree with Sperow that the government’s notice of its intent to seek an increased sentence due to a prior conviction was insufficient under 21 U.S.C. § 851(a). It is well established that one of the purposes of § 851 is to “ensure[ ] proper notice so a defendant is able to challenge the information ... [and] make an informed decision about whether or not to plead guilty.” United States v. Hamilton, 208 F.3d 1165, 1168 (9th Cir.2000) (citations omitted); see also Vadas v. United States, — F.3d —, —, 2007 WL 1288335, *5 (2d Cir.2007) (noting one of the purposes of § 851 is “to allow defendant to have ample time to determine whether to enter a plea or go to trial and plan his trial strategy with full knowledge of the consequences of a potential guilty verdict”) (quoting United States v. Williams, 59 F.3d 1180, 1185 (11th Cir.1995)); United States v. Cooper, 461 F.3d *1227850, 854 (7th Cir.2006) (“The two purposes of the Section 851 notice provision are: (1) to allow the defendant to contest the accuracy of the prior conviction ... and (2) to ensure the defendant has full knowledge of a potential guilty verdict.”). This purpose was frustrated by the government’s ambiguous motion to strike the second paragraph of the indictment.
The § 851 notice stated that it sought “a mandatory minimum term of imprisonment of ten (10) years imprisonment since this offense involves more than 100 kilograms of marihuana and because defendant has a prior conviction in United States District Court for the Southern District of California,” and attached a copy of the judgment in the prior conviction. Subsequently, after determining that the weight of the marijuana involved was less than 100 kilograms, the government “move[d] to strike the second paragraph of the grand jury indictment, which allegation established an enhanced penalty.” (Emphasis added).
The effect the government’s motion to strike had on the § 851 notice is susceptible to two interpretations. As the government now argues, the notice could be read as setting forth two alternative grounds for the enhancement: (1) that the amount of marijuana exceeded 100 kilograms and (2) that Sperow had a prior conviction. Under this reading, either ground would support an enhancement and the motion to strike negated only the drug quantity ground. As Sperow argues, however, an equally (if not more) plausible reading is that the motion intended to drop the enhancement altogether — an understanding the government itself initially adopted.
The drug quantity and prior conviction grounds in the § 851 notice can be read conjunctively. That is, the government pm-sued the enhancement because “this offense involves more than 100 kilograms of marihuana and because defendant has a prior conviction.” (Emphasis added). So read, the failure of either of these predicates would revoke the entire notice of enhancement. This reading is all the more reasonable given the language of the motion to strike, which specified that the allegation to be struck was that “which ... established an enhanced penalty,” without any mention of a continuing intent to seek an enhanced penalty on an alternative ground.
Most persuasive, the government itself acted as if its motion to strike invalidated the sentence enhancement. First, the prosecutor stated at trial, “The sentence of the defendant can be no more than 20 years. I’ve moved to strike, and I presume you allowed the motion to strike, the mandatory minimum language.” Twenty years is the maximum penalty allowed under 21 U.S.C. § 841(b)(1)(C) for a conviction involving between 50 and 100 kilograms of marijuana where no prior conviction is alleged. The maximum if the defendant has a prior conviction for a felony drug offense is 30 years. See § 841(b)(1)(C). Second, when the probation office inquired about the status of the notice of enhancement in light of the stricken paragraph of the indictment, the government responded that “the enhancement was gone.” In its presentence report, the probation office stated that “[bjased primarily on this assertion by the government and [its] failure to mention the notice of enhanced penalty at trial, the probation office believed the enhancement was gone.”
The government’s reliance on United States v. Severino, 316 F.3d 939 (9th Cir.2003) (en banc), embraced by the dissent, for the proposition that a § 851 notice is sufficient where the defendant “will have no trouble understanding which prior conviction the prosecutor means to identify” is misplaced. Id. at 943-44. Severino ad*1228dressed a challenge to the accuracy of the prosecutor’s description of the previous crime, and, in contrast to this case, we explicitly noted that the defendant could not “reasonably assert that he was blindsided by the government” or “reasonably assert that he entered his plea expecting anything less than a 10-year mandatory minimum sentence.” Id. at 945. That obviously was not the case here given the motion to strike, which rendered the § 851 notice fatally defective. See Hamilton, 208 F.3d at 1168.
We disagree with the dissent’s implication that initial compliance with § 851(a)’s four procedural requirements makes the government’s notice to seek a sentence enhancement immune from challenge if later modified or withdrawn. Here, after properly filing its § 851 notice, the government’s own ambiguous filings created the plainly reasonable impression — evidenced by the government’s own later statements — that the notice had been withdrawn and was no longer effective. There is no doubt that Sperow was on notice that the government initially intended to seek a sentence enhancement based on a particular prior conviction. The question here is whether a reasonable person in Sperow’s position would have known that the government continued with that intention despite its apparent withdrawal of the § 851 notice — knowledge that § 851 requires a defendant to have and that could have affected Sperow’s plea bargain or trial strategies. We do not suggest that Sper-ow’s purely subjective belief regarding the government’s abandonment of the sentence enhancement governs the outcome here. Rather, it is the government’s own actions and statements that would have led an objectively reasonable person to conclude that the government no longer intended to' seek a sentence enhancement on any basis, and in fact did lead the probation office to so inquire and be told that “the enhancement was gone.” 1
We therefore vacate Sperow’s sentence and remand for resentencing without the enhancement.
Conviction AFFIRMED; sentence VACATED and REMANDED for resen-tencing.
. Whatever the merits of the dissent’s suggestion that prosecutors might include a disclaimer in their § 851 notices advising defendants that only explicit, signed written withdrawal statements are binding, see Dissent at 1230 n.4, we do agree that clarity of expression is to be encouraged. We doubt, however, that a “wise” prosecutor would erroneously state in court that the defendant was subject to a maximum penalty that did not include an enhancement, lead the probation office to believe the "enhancement was gone” but then seek the very enhancement it had previously disclaimed.