Fleming appeals his conviction and sentence for being a felon in possession of a firearm in violation of 18 U.S.C. § 922(g)(1). We affirm.

I. BACKGROUND

In the early morning of October 12, 1991, police officers responded to reports of a disturbance in St. Louis. A man with a gun was threatening people on a street corner. The man fled and the officers chased him. During the chase, the man fired a shot at the pursuing officer and then escaped. Shortly thereafter, witnesses identified the man as Gerald Fleming. Upon investigation, the officers determined that Fleming sometimes resided with his girlfriend and that he might return to her apartment. That afternoon, the girlfriend’s neighbor contacted the police to report that Fleming had returned to the apartment. While the officers were en route to the apartment, they were informed by radio that another neighbor had reported hearing several gunshots coming from the girlfriend’s apartment. Police entered the apartment without a warrant where they found Fleming and a 357-magnum with four spent shells. Fleming was arrested at the scene.

Fleming was indicted for being a felon in possession of a firearm. The first trial in this case resulted in a mistrial. After a second trial to a jury, he was convicted. The district court sentenced him to 87 months for the offense.^[1]

II. DISCUSSION

Fleming first challenges the legal sufficiency of the indictment. He contends that the district court erred in denying his motion for a bill of particulars.^[2] According to Fleming, he was unable to frame a defense to the charge because he could not determine whether the possession charge was for the morning or the afternoon incident.

An indictment is legally sufficient on its face if it contains all of the essential elements of the offense charged, fairly informs the defendant of the charges against which he must defend, and alleges sufficient information to allow a defendant to plead a conviction or acquittal as a bar to a subsequent prosecution. United States v. Young, 618 F.2d 1281, 1286 (8th Cir.), cert. denied, 449 U.S. 844, 101 S.Ct. 126, 66 L.Ed.2d 52 (1980). An indictment will ordinarily be held sufficient unless it is so defective that it cannot be said, by any reasonable construction, to charge the offense for which the defendant was convicted. Id. To establish reversible error from the denial of a motion for a bill of particulars, a defendant must show that he was actually surprised at trial and suffered prejudice from the denial. United States v. Stephenson, 924 F.2d 753, 762 (8th Cir.), cert. denied, — U.S. —, 112 S.Ct. 63, 116 L.Ed.2d 39 (1991).

Fleming’s protest is specious. The superseding indictment charged Fleming with possession of a firearm on October 12, 1991. Evidence relating to both the morning incident and the afternoon incident was adduced at the evidentiary hearing on the motion and at the first and second trials. It is clear from the record that the parties knew the trial court regarded both incidents as “one possession through a series of continuous acts.” Transcript of Sentencing Hearing at 3-118 (September 4, 1992). At the hearing on Fleming’s motion, police officers testified about the morning incident. Fleming’s counsel then conceded “[n]ow, at least, we know that they are alleging that it’s the same weapon earlier in the morning as it is in the afternoon. ... [E]ven if the Government won’t respond specifically to the bill of particulars, at least we know what evidence they’re going to be submitting.” Transcript of Arraignment and Evidentiary Hearing at 166 (January 9, 1992). Whether the prosecution focused on events which occurred in the morning or the afternoon of October 12, 1991, or both, is of no consequence. We have[*1266] reviewed the indictment at issue and find it legally sufficient.

Fleming also asserts that the district court erred in overruling his motion to suppress. We have reviewed the transcript of the evidentiary hearing on that motion and find overwhelming evidence to support the Magistrate Judge’s finding that there were exigent circumstances to justify the warrant-less search.^[3] See United States v. Fleming, No. 91-224CR(5), Memorandum, Order and Recommendation of United States Magistrate Judge at 11-12, 1992 WL 546728 (E.D.Mo. March 26,1992). The district court adopted those findings and recommendations. United States v. Fleming, No. 91-224CR(5), Order (E.D.Mo. April 8, 1992). We agree with the district court’s rationale and affirm for the reasons set forth in its well-reasoned opinion. See 8th Cir.R. 47B.

Fleming next challenges the district court’s application of the United States Sentencing Guidelines (“Guidelines”). He first asserts that the district court misapplied U.S.S.G. § 2K2.1., which sets the base offense levels for firearms offenses and includes provisions for cross-referencing to other provisions. Fleming bases his vague challenge to the application of section 2K2.1 on assertions that the district court applied the wrong burden of proof. Though his argument is not explicit, we assume that Fleming is making a constitutional challenge to use of the cross-reference provisions. The thrust of his argument seems to be the fundamental unfairness of considering uncharged conduct in sentencing under the Guidelines.

Whatever the intuitive appeal of his position, the issue is not “simmer[ing] in confusion” as he contends. A district court’s consideration of uncharged conduct in sentencing does not violate a defendant’s constitutional rights if the government proves such conduct by a preponderance of the evidence. United States v. Galloway, 976 F.2d 414, 422-25 (8th Cir.1992) (en banc) (because defendant’s uncharged crimes are treated as sentencing factors, rights to indictment, jury trial, and proof beyond a reasonable doubt do not come into play), cert. denied, — U.S. —, 113 S.Ct. 1420, 122 L.Ed.2d 790 (1993). Although the specific issue in Galloway was whether the relevant-conduct guideline (U.S.S.G. § 1B1.3) was constitutional, the same analysis applies to the constitutionality of the cross-referencing provision. United States v. Smith, 997 F.2d 396, 400 (8th Cir.1993). The relevant conduct guideline and the cross-referencing provision similarly allow a district court to consider uncharged conduct in determining a defendant’s offense level. Id.; see also United States v. Humphries, 961 F.2d 1421, 1422-23 (9th Cir.1992) (per curiam) (upholding as constitutional district court’s cross-reference to sections 2X1.1 and 2A2.2, even though defendant had been charged only with being a felon in possession of a firearm). Here, we find the government proved the aggravated assault by at least a preponderance of the evidence and the district court therefore properly applied the cross-referencing provision.

Fleming also challenges the district court’s calculation of his sentence. At the sentencing hearing, the district court found that Fleming had assaulted a police officer and fired a shot. The district court concluded that a cross-reference to aggravated assault was proper. The district court adopted the recommendations of the Presentence Report (PSR) and sentenced Fleming at the upper end of the guideline range.^[4] The dis[*1267] trict court based its findings on the testimony adduced at trial. We find ample evidence to support the district court’s finding and find no error in its application of the Guidelines.

Fleming last contends that the district court erred in making a victim-related adjustment. Section 3A1.2(b) of the Guidelines provides a three-level increase if “during the course of the offense or immediate flight therefrom, the defendant ... knowing or having reasonable cause to believe that a person was a law enforcement or corrections officer, assaulted such officer in a manner creating a substantial risk of serious bodily injury.” Fleming contends, without authority, that being a felon in possession of a firearm has no official victim since the “victim” is society in general. The district court found that “during the course of this offense, the defendant, in fact, was quite aware that the person that he was involved with when he had possession of the gun was a law enforcement officer; and that, in fact, he did assault such law enforcement officer in a manner that created a substantial risk of serious bodily injury.” Transcript of Sentencing Hearing at 3-139-40 (Sept. 4, 1992). This finding is amply supported by the evidence. A three-level increase is appropriate in a prosecution for being a felon in possession of a firearm when an assault on a police officer is involved. See United States v. Hooker, 997 F.2d 67 (5th Cir.1993).

III. CONCLUSION

For the reasons stated above, the judgment of the district is affirmed.