Opinion by Judge KOZINSKI; Concurrence by Judge FLETCHER.
KOZINSKI, Circuit Judge.We determine whether the government charged these criminal defendants in the right place at the right time.
I.
Ronald R. Jensen and Frederick Carl Peterson were jointly charged with two counts of sending the Arctic Enterprise, a fish processing ship,1 to sea in an unseaworthy condi*669tion, 46 U.S.C. § 10908. Jay Clifford was separately charged with one count of violating the same provision with respect to the Aleutian Enterprise, another fish processing ship. Defendants moved to dismiss the first count of the Jensen/Peterson indictment and the only count of the Clifford indictment. They argued that venue in the Western District of Washington was improper because, at the time the crimes were alleged to have been committed, the vessels.were either in Alaskan waters or on the high seas. To support their contention, defendants attached a marine accident report, a marine casualty report and two affidavits of a marine investigator who had examined the vessels’ logbooks.
The government then moved to dismiss the indictments and substitute informations charging Jensen and Peterson with two counts, and Clifford with one count, of operating a vessel in a grossly negligent manner, 46 U.S.C. § 2302(b). The district court granted the government’s request, but the parties agreed that defendants’ motion to dismiss would be applicable to the new charges. The district court then dismissed the charges for improper venue, basing its decision on the evidence provided by defendants as to the location of the vessels.
II
Because these appeals arise from defendants’ pretrial motion to dismiss, see Fed.R.Crim.P. 12(b)(2), we must presume the truth of the allegations in the charging instruments. United States v. Caicedo, 47 F.3d 370, 371 (9th Cir.1995); United States v. Buckley, 689 F.2d 893, 897 (9th Cir.1982), cert. denied, 460 U.S. 1086, 103 S.Ct. 1778, 76 L.Ed.2d 349 (1983). In addition, “[a] defendant may not properly challenge an indictment, sufficient on its face, on the ground that the allegations are not supported by adequate evidence.” United States v. Mann, 517 F.2d 259, 267 (5th Cir.1975), cert. denied, 423 U.S. 1087, 96 S.Ct. 878, 47 L.Ed.2d 97 (1976). “A motion to dismiss the indictment cannot be used as a device for a summary trial of the evidence.... The Court should not consider evidence not appearing on the face of the indictment.” United States v. Marra, 481 F.2d 1196, 1199-1200 (6th Cir.), cert. denied, 414 U.S. 1004, 94 S.Ct. 361, 38 L.Ed.2d 240 (1973).
The district court thus erred in considering the documentation provided by the defendants. By basing its decision on evidence that should only have been presented at trial, the district court in effect granted summary judgment for the defendants. This it may not do. United States v. Critzer, 951 F.2d 306, 307 (11th Cir.1992) (per curiam) (“There is no summary judgment procedure in criminal cases. Nor do the rules provide for a pre-trial determination of the evidence.”).2
The facts alleged in the two informations, when taken as true, are sufficient to establish venue in the Western District of Washington. The Clifford information alleges that he committed the sole count “within the special maritime and territorial jurisdiction of the United States and upon the high seas.” Clifford Information at 2. 18 U.S.C. § 3238 states:
The trial of all offenses begun or committed upon the high seas ... shall be in the district in which the offender ... is arrested or is first brought; but if such offender or offenders are not so arrested or brought into any district, an indictment or information may be filed in the district of the last known residence of the offender....
The Clifford information does not allege that he was • ever arrested or brought into any district; it does allege that “[t]he last known residence of JAY CLIFFORD is within the Western District of Washington.” Clifford Information at 1. Therefore, the information, *670on its face, is sufficient to establish venue in the Western District of Washington.
The Jensen/Peterson information alleges that they committed count one “within the Western District of Washington, and within the special maritime and territorial jurisdiction of the United States and upon the high seas.” Jensen/Peterson Information at 2. The information also alleges that the last known residences of both men were within the Western District of Washington. The government therefore argues that venue is proper as to Jensen and Peterson, just as with Clifford, in the Western District of Washington under 18 U.S.C. § 3238. Defendants counter that section 3238 applies only when the crime is committed exclusively on the high seas and not in any district: Because the information alleges that the crime was committed on the high seas and within a district, section 3238 is inapplicable.
We do not reach this issue, as it makes no difference in this case. If section 3238 applies, then venue in the Western District of Washington is proper as the place of Jensen’s and Peterson’s last known residences. If section 3238 is not applicable, venue is still proper as the place where the crime was committed. See U.S. Const, art. Ill, § 2, cl. 3 (“The Trial of all Crimes ... shall be held in the State where the said Crimes shall have been committed....”); Fed.R.Crim.P. 18 (“[T]he prosecution shall be had in a district in which the offense was committed.”); cf. 18 U.S.C. § 3237 (offenses begun in one district and completed in another).
REVERSED and REMANDED.
. This type of vessel — essentially a floating fish processing plant — may employ 100 or more workers.
. While venue is not technically an element of the crime, it must still be proved by the government at trial. United States v. Kaytso, 868 F.2d 1020, 1021 (9th Cir.1989). We express no view as to the proper disposition of a motion for acquittal for lack of venue, should one be made after the close of the government’s case-in-chief. See United States v. Ochoa-Torres, 626 F.2d 689, 691-92 (9th Cir. 1980) (explaining standards for motion of acquittal for lack of venue); cf. United States v. Durades, 607 F.2d 818, 819-20 (9th Cir.1979) (reversing conviction because of variance between evidence and indictment that made venue improper).