Chicago Police Officer William Cozzi shackled a man to a wheelchair in a hospital and then repeatedly bludgeoned him in the head and face with a sap. 1 He now appeals the district court’s denial of his motion to dismiss the indictment charging him with violating his victim’s civil rights. He also appeals the district court’s use of the sentencing guideline for aggravated assault rather than the guideline for civil rights violations. Neither of the issues Cozzi raises on appeal has merit. We therefore affirm Cozzi’s conviction and sentence.
I. Background
Randle Miles was stabbed during an altеrcation in August 2005. He then drank heavily before an ambulance came and took him to Norwegian American Hospital in Chicago. William Cozzi, a Chicago Po *727 lice Department officer, was dispatched to the scene of the altercation, but eventually made his way to the hospital to talk with Miles. Miles was apparently being loud and abusive to hospital staff, so Cozzi placed Miles under arrest, handcuffing him to a wheelchair and shackling his legs. While several witnesses looked on, Cozzi then hit Miles repeatedly with a non-police-issued sap. Cоzzi later falsified a police report and misdemeanor complaints claiming that Miles had thrown punches and that Cozzi had struck Miles with his hand; he never mentioned the sap. The incident, however, was caught on tape by a hospital security camera. The hospital contacted the Chicago Police Department’s Office of Professional Standards (“OPS”) later that month to report the incident.
OPS started an investigation the day after the hospital reported the incident. It interviewed several witnesses and obtained a copy of the video and 911 calls related to the event. On September 14, 20, and 21, 2005, OPS interviewed Cozzi. He was first given administrative rights, which compelled him to make a statement or lose his job, but which also guaranteed that his statements could not be used against him in any future criminal proceedings. Ultimately, OPS concluded that Cozzi should be terminated from the Chicago Police Department.
In December 2005, Cozzi was indicted in Cook County for aggravated felony battery and official misconduct. He pled guilty in May 2007 to a reduced misdemeanor battery charge, for which the court sentencеd him to eighteen months’ probation and required him to attend anger management classes. The superintendent of the Chicago Police Department filed charges in April 2006 to fire Cozzi from the police department. The Chicago Police Board held public hearings in July and August 2007 in which Cozzi was called as an adverse witness. In October 2007, the Police Board decided 6-2 to suspend Cozzi for two years rather than terminate him. His suspension was made retroactive to April 2006. The Cook County Circuit Court Chancery Division affirmed the decision in July 2008 over the city’s appeal.
Former FBI agent Jody Weis was scheduled to become the Chicago Police Department’s superintendent on February 1, 2008. In January 2008, Weis told the press that he was unhappy with the Police Board’s decision and promised to review Cozzi’s case. That same month, Weis sent two emails to an agent in the FBI’s Chicago field office, asking whether the FBI had investigated Cozzi for civil rights violations and mentioning that the former superintendent had unsuccessfully tried to fire Cozzi and that Cozzi had “falsified his statement.” Weis also attached a copy of the video clip of the incident. The FBI had not yet started an investigation, but it quickly did. In April 2008, a federal grand jury indicted Cozzi on one count of violating 18 U.S.C. § 242 by depriving Miles of his right to be free from the unreasonable use of force. None of the federal prosecutors saw or reviewed Cozzi’s immunized statements, and his protected statements were removed from the OPS files that were turned over to the federal grand jury.
Cozzi filed a motion in the district court seeking to have the indictment dismissed on the grounds that the government had improperly used his immunized statements in violation of
Garrity v. New Jersey,
II. Analysis
Cozzi argues on appeal that the district court should have dismissed the indiсtment because Weis’s review of his protected statements and subsequent tip to the FBI constituted an improper use of his statements in violation of
Garrity,
A. Use of Immunized Statements
We review the district court’s legal conclusions
de novo
and its factual findings for clear error.
See United States v. Greve,
Later, in
Kastigar,
Some courts have read
Kastigar
expansively to prohibit not only the introduction of compelled testimony into evidence, but also “assistance in focusing the investigation, deciding to initiate prosecution, refus
*729
ing to plea-bargain, interpreting evidence, planning cross-examination, and otherwisе generally planning trial strategy.”
See, e.g., United States v. McDaniel,
We held in
Velasco
that “the mere tangential influence that privileged information may have on the prosecutor’s thought process in preparing for trial is not an impermissible ‘use’ of that information.”
Id.
This approach acknowledges that “[t]he burden on the prosecution to establish an independent source for evidence against a defendant is a heavy one indeed,” but that it should not be an impossible one to bear.
Id.
We re-affirmed
Velasco’s
“tangential influence” approach in
United States v. Bolton,
Cozzi argues that the Supreme Court’s decision in
United States v. Hubbell,
Against this backdrop, Cozzi argues that his conviction should be overturned because he claims that his statements were improperly used against him. Cozzi’s theory on appeal of who used his statements improperly has gradually expanded from initial briefing to oral argument. In his initial brief, in which he had the opportunity to define the scope of the appeal, Cozzi argued only that Weis’s tip to the FBI constituted an improper use of his protected statements. But in his reply brief, Cozzi added a complaint that the federal prosecutors may have been exposed to, and thus afforded the opportunity to improperly use, his protected statements because the OPS file contained references to his statements, although the statements themselves had been removed from the file. Then, at oral argument Cozzi added the OPS investigators to his list, arguing that the government' had not met its burden to show that the OPS investigators had not made improper use of his statements in conducting their investigation.
*730
An appellant cannot raise new theories or issues in a reply brief or at oral argument,
United States v. Wescott,
Turning nоw to Cozzi’s argument regarding Weis, we find that Weis’s tip to the FBI did not constitute an improper use of Cozzi’s protected statement. As an initial matter, we note that the question of whether Weis reviewed Cozzi’s protected statements remains unanswered because the government did not see fit to submit an affidavit from Weis explaining what he did or did not read. We also do not know, although we may speculate, why Weis referred Cozzi’s case to the FBI. Because the government bears the burden to prove that the statements were not improperly used, we think it fair to аssume for purposes of this appeal that Weis read the protected statements, and we may even assume that he was motivated to email his colleagues at the FBI because of what the protected statements contained. However, those assumptions do not end our inquiry into whether Cozzi’s statements were improperly used, thus requiring us to overturn his conviction.
There is no question that
Kastigar
bars not only evidentiary use of compelled testimony but also non-evidentiary, or derivative, use of the same. At issue here is the scope of derivative-use immunity. The ease lаw does not say that a defendant’s immunized statements may never be used by anyone under any circumstances.
Garrity,
for example, clearly contemplated that the officers’ compelled testimony could be used for internal investigation purposes.
Kastigar
immunity is primarily concerned with the prosecutor’s use of compelled testimony because it is the prosecutor who actually initiates and pursues criminal proceedings against a defendant. Thus,
Kastigar
held that use or derivative-use immunity is co-extensive with the Fifth Amendment privilege because it “prohibits
the prosecutorial authorities
from using the compelled testimony in any respect. ...”
Cozzi has not brought to our attention a single case where a non-prosecutor’s use of a compelled statement, by itself, was held to be a violation of the defendant’s Fifth Amendment privilege. To be sure, the government has not cited any cases where a non-prosecutor’s use of a compelled statement was held not to be a violation of the defendant’s Fifth Amendment privilege. But see id. at 1474 (concluding that the prosecutor’s use, if any, of protected statement was not improper). The dearth of cases in either category further supports the proposition that it is the prosecutor’s use of a compelled statement that is of primary concern.
That is not to say that other individuals’ use of protected statements cannot run afoul of a defendant’s immunity rights.
See, e.g., United States v. North,
Turning now to the facts before us, Cozzi argues that Weis’s tip to the FBI was an impermissible use of his protected statements because “but for” Weis’s tip there would not have been a federal investigation and indictment. Cozzi argues that, like the compelled discovery documents in Hubbell, Weis’s tip was the first step in a chain of evidence that led to criminal proceedings against him. We disagree. We find that Weis’s tip alone, without communicating the substance of Cozzi’s statements to federal officials, does not constitute an impermissible non-evidentiary use of the compelled statement.
We are not concerned with how
Weis
may have influenced the federal investigation, but rather how Cozzi’s
statements
influenced the investigation. When framed properly, it is clear that Cozzi’s statements could not have had even a tangential influence on the federal prosecu
*732
tors. Weis did not tell his former colleague at the FBI what Cozzi’s statеments contained, and we do not think that simply-saying a statement was “falsified,” by itself, is enough to impute improper use of the statement to prosecutorial authorities.
Cf. Bolton,
We are not persuaded by Cozzi’s argument that
Hubbell
compels a different outcome. We read
Hubbell
as an affirmation of the doctrine, fully explained in
Kastigar,
Here, the chain of evidence was cut off between Weis and federal investigators because Weis did not communicate any of the contents of the statements in his email. What’s more, in Hubbell it was the defendant’s protected statement itself that prompted the federal investigation. Here, it was not the statement itself but a tip by a third party that prompted the investigation. As discussed above, we evaluate a nоn-prosecutor’s use of protected testimony only as it relates to actual criminal proceedings against the defendant. Whatever role the statements might have had in motivating Weis’s tip is at least one step too far removed from the actual federal investigation and prosecution to justify overturning Cozzi’s conviction. On the facts before us, we conclude that the compelled statements, if they had any influence at all, could have had only a tangential influence on the federal investigation and prosecution.
Finally, we do not think that our decision today hearkens back to the now repudiated “silver platter” doctrine. That phrase arises from the practice of state law enforcement officials obtaining evidence in violation of a defendant’s constitu
*733
tional rights and then handing it over to federal prosecutors, who were permitted to use the evidence because they were not the wrongdoers. The practice has since been repudiated in no uncertain terms.
See Elkins v. United States,
B. Applicable Sentencing Guideline
Cozzi also argues that the district court should have used the civil rights guideline, rather than the aggravated assault guideline, to calculate the base offense level for sentencing purposes. A court sentencing a defendant guilty of violating 18 U.S.C. § 242 starts with § 2H1.1 of the sentencing guidelines. To calculate the correct base offense level, § 2H1.1 directs the court to apply the greatest of either — as applicable here — “the offense level from the offense guideline applicable to any underlying offense” or “10, if the offense involved (A) the use or threat of force against a person....” Subsection (b) increases the base offense level by 6 levels “[i]f (A) the defendant was a public official at the time of the offense; or (B) the offense was committed under color of law....” Application Note 1 of § 2H1.1 defines the “Offense guideline applicable to any underlying offense” as “the offense guideline applicable to any conduct established by the offense of conviction that constitutes an offense under federal, state, or local law (other than an offense that is itself covered under Chapter Two, Part H, Subpart 1).”
The government urged the district court to use § 2A2.2 of the sentencing guidelines to calculate Cozzi’s base offense level. Section 2A2.2 applies to “aggravated assault,” which is defined as “a felonious assault that involved (A) a dangerous weapon with intent to cause bodily injury (i.e., not merely to frighten) with that weapon; (B) serious bodily injury; or (C) an intent to commit another felony.” U.S.S.G. § 2A2.2, Application Note 1. The government argued that the conduct to which Cozzi pled guilty fell squarely within the definition of aggravated assault— namely, that Cozzi repeatedly struck Miles in the face with a sap — a dangerous weapon. The district court adopted the government’s (and the pre-sentence report’s) recommendation to use § 2A2.2 to calculate the base offense level.
The district court correctly applied the sentencing guidelines in calculating the appropriate sentencing range for Cozzi. The plain language of § 2H1.1 directs a court to apply the sentencing guideline applicable to the underlying offense (here, aggravated assault) if it would produce a greater base offense level than the base offense lеvel premised solely on § 2H1.1. In this regard, § 2H1.1 “provides a floor, not a ceiling.”
United States v. Byrne,
*734 Cozzi argues that the district court’s use of § 2A2.2 was also improper because there was no underlying offense due to the fact that he was only charged with and plеd guilty to one count, a civil rights violation. But the fact that there is only one count in his indictment does not eliminate Cozzi’s conduct — he could only violate Miles’s civil rights by doing something. It is that something that constitutes the underlying offense for purposes of § 2H1.1, regardless of how many substantive counts with which Cozzi was charged.
Cozzi also argues that because § 2H1.1 takes into account aggravating factors, there was no need to resort to § 2A2.2. Cozzi is correct that both § 2H1.1 and § 2A2.2 could account for his underlying conduct. However, the plain language of § 2H1.1 specifically directs the district court to use the guideline that produces the greatest base offense level. Section 2A2.2 produces a higher base offense level than § 2H1.1, so the district court was correct in using the former section as a starting point for calculating Cozzi’s appropriate sentencing range.
Cozzi also argues that the aggravated assault guideline was not intended to cover civil rights violations because it does not mention 18 U.S.C. § 242 as an applicable code section and a civil rights violation is not like the other substantive crimes specifically mentioned. Of course, here the cross-reference comes from the civil rights guideline and not the aggravated assault guideline. There are myriad ways to violate someone’s civil rights, so as a matter of policy and economy it makes sense to have a single, flexible cross-reference in the civil rights guideline, rather than include a reference to the civil rights guideline in every conceivable section covering conduct that might also violate a victim’s civil rights.
Cozzi’s argument that using the aggravated assault guideline will produce sentencing disрarities between him and other civil rights violators is without merit. Section 2H1.1 is in fact designed to ensure that there are no sentencing disparities between someone who commits aggravated assault and someone who commits aggravated assault that also violates the victim’s civil rights. With a view toward the underlying conduct, there is no risk that referencing the aggravated assault guideline here will result in Cozzi receiving a sentence inappropriately disparate from other similarly situated defendants.
Finally, Cozzi argues that the aggravated assault guideline doеs not apply to him because he only pled guilty to a misdemeanor in state court and the guideline is expressly limited to “felonious assault.” It is Cozzi’s conduct, however, and not his state court plea that constitutes the underlying offense for purposes of § 2H1.1. See U.S.S.G. § 2H1.1, Application Note 1. In his federal plea agreement, Cozzi acknowledged that he hit Miles in the face with a dangerous weapon. He can make no serious argument that the conduct to which he pled guilty does not constitute felonious assault, his bargain in state court notwithstanding. Accordingly, the district court did not err in finding that § 2A2.2 was applicable to Cozzi’s underlying offense.
III. Conclusion
There was no improper use of Cozzi’s immunized statements, and the district court correctly calculated the applicable guideline range. We therefore Affirm Cozzi’s conviction and sentence.
Notes
. Although the record does not contain a description of the actual weapon that Cozzi used, a sap is generally described as “a leather-covered flat or round piece of lead with a spring handle, although it could contain lead shot rather than a solid piece of metal.” Jack Lewis et al., The Gun Digest Book of Assault Weapons 42 (7th ed. 2007).
