OPINION OF THE COURT
Rogers Lockett argues that the District Court erred by denying his motion to suppress because the police exceeded the scope of his consent to search his suitcase and unlawfully seized him, rendering the search of his backpack involuntary. Additionally, he submits that he is no longer bound by the dictates of his plea agreement as a result of the Supreme Court’s decision in
United States v. Booker,
543 U.S. -,
I.
Lockett was sitting on a bench in the Amtrak 30th Street Train Station in Philadelphia. After watching Lockett for approximately fifteen minutes, Special Agent Carl Giardinelli 1 and Corporal William Burdette 2 approached him. Burdette showed Lockett his badge, identified himself, and asked if Lockett would answer a few questions. After Lockett answered “yes,” Burdette sat down on the bench approximately two feet to Lockett’s right and Giardinelli remained standing a few feet to the right of Burdette. Burdette asked Lockett some questions about his travel and Lockett explained that he was from Philadelphia but was traveling to Boston, where he attends Newbury College. Burdette examined Lockett’s identification and train ticket and then returned them to Lockett.
Burdette explained to Lockett that he and Agent Giardinelli were looking for contraband including narcotics, large sums of money, guns, and other weapons. He asked Lockett if he had any of these items in his possession; Lockett said that he did not. Then Burdette asked Lockett if the rolling suitcase on the seat next to Lockett belonged to him and Lockett admitted that it did. Burdette asked if he could look in the suitcase and Lockett said “yes.” Lockett then placed the suitcase on the floor and started to open it, at which point Burdette said, “that’s okay, I can get that.” Lockett responded, “no, I’ll get it,” but Burdette repeated, “no, that’s okay, I can get it.” Burdette then opened the bag.
After opening the suitcase, Giardinelli and Burdette saw three large plastic bags that contained numerous small clear plastic bags, which the Officers recognized as the type of bags commonly used to package illegal drugs. On one of the larger bags was a picture of a marijuana leaf. Burdette pushed the rolling suitcase over to Giardinelli, who continued searching-through it.
While Giardinelli was searching the suitcase, Burdette asked Lockett if the other bag, a backpack, belonged to him and Lockett said “yes.” Burdette asked if he could look in the backpack and Lockett said “yes” and handed the backpack to Burdette.
As Giardinelli was searching the rolling suitcase, his finger hit a metal object and he realized it was a gun. 3 He yelled “gun” in a loud voice so as to get the attention of Burdette and the other law enforcement officers in the vicinity. Burdette and Offi *210 cer Sean Martin, an Amtrak police officer, handcuffed Lockett and walked him from the public area of the train station to the Amtrak police station, which was a short distance away within the same building. Lockett was handcuffed to a bench in the Amtrak police station while Burdette physically searched through the bags with Giardinelli observing nearby. 4 After the search, Officer James' Corbett, a member of the Philadelphia Police Department, read Lockett his Miranda rights and then asked him who owned the guns. Lockett answered, “the guns are mine.” Corbett then asked Lockett from whom he obtained the firearms, at which point Lockett said that he wanted to talk to a lawyer. At this point all questioning of Lockett stopped.
II.
Lockett was charged with possession of marijuana with the intent to distribute, possession of firearms in connection with a drug trafficking offense, and possession of firearms with obliterated serial numbers. Lockett filed a motion to suppress the physical evidence and the statements he made to the law enforcement officers. After a hearing, the District Court denied the Motion, with the following detailed findings of fact and conclusions of law: (1) the encounter between Burdette, Giardi-nelli, and Lockett was not coercive and did not constitute a stop or seizure under the Fourth Amendment; (2) a reasonable person in Lockett’s position would have felt free to refuse to talk to Giardinelli and Burdette; (3) Lockett voluntarily gave his consent to search his rolling suitcase and backpack; (4) Lockett never revoked his consent to the searches of his rolling suitcase and backpack; (5) Lockett was not in custody until his arrest after Giardinelli discovered the gun in his rolling suitcase; and (6) Lockett voluntarily, knowingly, and intelligently waived his Miranda rights prior to saying “the guns are mine.”
Pursuant to a written guilty plea agreement, Lockett pleaded guilty to all charges, reserving his right to appeal the denial of his motion to suppress. The plea agreement expressly limited the defendant’s right to appeal, excepting only an appeal based on a claim that the defendant’s sentence exceeded the statutory maximum, that the sentencing judge erroneously departed upwards from the guidelines range, or that the district court erroneously decided the suppression issues.
The District Court imposed a sentence of six months imprisonment for possession of marijuana with intent to distribute and possession of firearms with obliterated serial numbers pursuant to the federal sentencing guidelines. The District Court also imposed a sentence of sixty months imprisonment to run consecutively for possession of firearms in furtherance of a drug trafficking crime, which is the statutory mandatory minimum. The total sentence was for 66 months imprisonment, five years of supervised release, a $2,000 fine, and a special assessment of $300. Lockett now appeals his conviction and sentence.
III.
This is an appeal from a final judgment of the District Court. We have appellate jurisdiction pursuant to 28 U.S.C. § 1291.
*211
We review a District Court’s denial of a motion to suppress for clear error as to the underlying factual findings and exercise plenary review over the District Court’s application of the law to those facts.
United States v. Perez,
IV.
A Seizure
Lockett asserts that he was unlawfully seized when he submitted to authority by relinquishing control of his suitcase. We do not agree.
It is well established that no seizure has occurred when an officer approaches an individual in a public place, identifies himself as a law enforcement agent, asks questions, asks to. search a person’s bags, or explains that he is conducting a narcotics investigation.
See Florida v. Royer,
Under similar circumstances, we have held that questioning of a traveler by police officers, followed by a request to search the traveler’s bags did not amount to a “seizure” of that traveler under the Fourth Amendment.
See Thame,
As in Thame, the encounter here took place in an open public area. The officers did not control or block Lockett’s movement. They did not retain Lockett’s papers or identification. And they did not tell Lockett that he was a suspect. We hold that the officers did not induce Lock-ett’s cooperation by coercion. In light of all the circumstances, a reasonable person would have felt free to terminate the encounter, and therefore Lockett was not “seized.”
B. Consent
Under the Fourth and Fourteenth Amendments, a search conducted without a warrant issued upon probable cause is “per se unreasonable ... subject only to a few specifically established and well-delineated exceptions.”
Schneckloth,
Lockett does not dispute the District Court’s finding of consent, but instead claims that he gave “limited consent” only *212 to a visual inspection. Lockett asserts that, even though counsel below may not have used the precise term “limited consent,” the legal issue remains the same: would the officers’ conduct have communicated to a reasonable person that Lockett was not free to decline the officers’ request.
The government contends Lockett waived the limited consent issue by failing to include it in his suppression motion. 5 Federal Rule of Criminal Procedure 12(b)(3) requires a defendant to file a suppression motion prior to trial, and Rule 12(f) provides that failure to do so constitutes a waiver. We agree that Lockett waived the limited consent issue.
It is well settled that arguments asserted for the first time on appeal are deemed to be waived and consequently are not susceptible to review in this Court absent exceptional circumstances.
See Brown v. Philip Morris, Inc.,
V.
Lockett. also maintains that his sentence is inconsistent with the Supreme Court’s recent decision in
United States v. Booker,
543 U.S. -,
Waivers of appeal, if entered knowingly and voluntarily, are valid, unless they work a miscarriage of justice.
United States v. Khattak,
Just as subsequent changes in the law do not undercut the validity of an appellate waiver, they do not render the plea itself invalid. The Supreme Court has explained that where subsequent developments in the law expand a right that a defendant has waived in a plea agreement, that change does not make the plea involuntary or unknowing or otherwise undo its binding nature.
See Brady v. United States,
Lockett asks us to invalidate his sentence because he did not know at the time he pleaded guilty that the Supreme Court would later hold that the Sentencing Guidelines are advisory. However, this change in the law cannot effect a change in his plea. As the Sixth Circuit has recently explained:
“[p]lea bargains always entail risks for the parties — risks relating to what evidence would or would not have been admitted at trial, risks relating to how -the jury would have assessed the evidence and risks relating to future developments in the law. The salient point is that a plea agreement allocates risk between the two parties as they see fit. If courts disturb the parties’ allocation of risk in an agreement, they threaten to damage the parties’ ability to ascertain their legal rights when they sit down at the bargaining table and, more problematically for criminal defendants, they threaten to reduce the likelihood that prosecutors will bargain away counts with knowledge that the agreement will be immune from challenge on appeal.”
Id.
at 461;
see also Young v. United States,
We join four other Courts of Appeals in reaching this conclusion.
See United States v. Bradley,
VI.
For the foregoing reasons, we will affirm the District Court’s decision that the search of Lockett’s luggage was not coercive and did not constitute a stop or seizure in violation of his rights under the Fourth Amendment. We will dismiss the remainder of his appeal as inconsistent with the appellate waiver in his plea agreement.
Notes
. Special Agent Giardinelli is an agent with the Drug Enforcement Agency.
. Officer Burdette is a Corporal with the Pennsylvania State Police assigned to the Bureau of Emergency and Special Operations and then reassigned to the Drug Enforcement Agency.
. The gun discovered by Giardinelli was an Intertec 9mm semi-automatic uzi-type weapon with an obliterated serial number.
. During the search at the police station, Bur-dette and Giardinelli found a Bryco Jennings 9mm semi-automatic pistol with an obliterated serial number loaded with twelve live rounds, as well as a magazine for the Intratec containing thirty rounds of ammunition. They also found approximately one pound of marijuana in the rolling suitcase. In addition, they found three notebooks and pictures in the backpack; two of the pictures were of Lockett and another individual holding handguns to each other's heads.
. The Government’s Brief notes that: "Lock-ett filed a Motion to Suppress Physical Evidence and Statement before the suppression hearing and filed a Supplemental Memorandum of Law in Support of Defendant's Motion to Suppress Physical Evidence and Statement after the hearing. In neither of these written submissions, nor in the oral argument immediately following the hearing, did Lockett claim that he gave consent only to a visual inspection of his suitcase or that the police search of his suitcase exceeded the scope of his limited consent.” (Appellee’s Br. at 27).
