opinion: UNITED STATES of America, Appellee, v. Harry Blake JOHNSON, Appellant.
  No. 71-1056.
  United States Court of Appeals, Fourth Circuit.
  Argued Aug. 31, 1971.
  Decided Nov. 26, 1971.
  Robert L. Dolbeare, Richmond, Va. (court-appointed counsel) [Obenshain, Hinnant & Dolbeare, Richmond, Va., on brief] for appellant.
  Rodney Sager, Asst. U. S. Atty., for the Eastern District of Virginia (Brian P. Gettings, U. S. Atty., on the brief) for appellee.
  Before BRYAN, CRAVEN, and BUTZNER, Circuit Judges.
  PER CURIAM:
  Harry Blake Johnson appeals his conviction of conspiracy and interstate travel in aid of racketeering in violation of 18 U.S.C. §§ 2, 371, and 1952. His principal assignment of error is the district court’s refusal to suppress evidence seized under the authority of a search warrant issued by a state justice of the peace. Johnson contends the evidence should have been excluded because Federal Rule of Criminal Procedure 41(a) requires that the state officer issuing a search warrant be a judge of a court of record. He makes no claim that the warrant or the search and seizure violated the fourth amendment. He relies on Lustig v. United States, 338 U.S. 74, 69 S.Ct. 1372, 93 L.Ed. 1819 (1948), Byars v. United States, 273 U.S. 28, 47 S.Ct. 248, 71 L.Ed. 520 (1927), and Navarro v. United States, 400 F.2d 315 (5th Cir. 1968), which hold that where federal officers participate, the search must be conducted according to federal standards. The district court admitted the evidence because in its opinion the federal agents did not participate in the search.
  The evidence disclosed that an informant told the F.B.I. of gambling operations that had come to his attention. He also notified the state police, who conducted an investigation. The state officers obtained a search warrant, searched the gamblers’ premises, seized and marked the evidence and retained custody of it. They also prosecuted charges against the operators of the gambling establishment in a state court. Later when the federal case was tried, they testified about the search and laid the foundation for the introduction into evidence of the articles that they had seized.
  Federal agents conferred with the state officers about the investigation, but they did not assist in obtaining the warrant. Three federal agents were present when the state officers searched the premises. They did not, however, join in the search, seize any evidence, or interrogate any suspects. We believe the district judge correctly held that the federal agents were present simply as observers and that they did not participate in the search. Cf. United States v. Coronna, 420 F.2d 1091 (5th Cir. 1970); Stonehill v. United States, 405 F.2d 738 (9th Cir. 1968), cert. denied, 395 U.S. 960, 89 S.Ct. 2102, 23 L.Ed.2d 747 (1969).
  Johnson also complains that his motion for a severance and mistrial should have been granted after the other defendants changed their pleas to guilty during the trial. We think the court’s instructions to the jury about this unexpected occurrence fully protected Johnson, and we find no abuse of discretion in the denial of the motion.
  Affirmed.
  . Federal Kule of Criminal Procedure 41(a) provides:
  “(a) Authority to Issue Warrant. A search warrant authorized by this rule may be issued by a judge of the United States or of a state, commonwealth or territorial court of record or by a United States commissioner within the district wherein the property sought is located.”
instruction: What follows is an opinion from a United States Court of Appeals.
  Intervenors who participated as parties at the courts of appeals should be counted as either appellants or respondents when it can be determined whose position they supported. For example, if there were two plaintiffs who lost in district court, appealed, and were joined by four intervenors who also asked the court of appeals to reverse the district court, the number of appellants should be coded as six.
  In some cases there is some confusion over who should be listed as the appellant and who as the respondent. This confusion is primarily the result of the presence of multiple docket numbers consolidated into a single appeal that is disposed of by a single opinion. Most frequently, this occurs when there are cross appeals and/or when one litigant sued (or was sued by) multiple litigants that were originally filed in district court as separate actions. The coding rule followed in such cases should be to go strictly by the designation provided in the title of the case. The first person listed in the title as the appellant should be coded as the appellant even if they subsequently appeared in a second docket number as the respondent and regardless of who was characterized as the appellant in the opinion.
  To clarify the coding conventions, consider the following hypothetical case in which the US Justice Department sues a labor union to strike down a racially discriminatory seniority system and the corporation (siding with the position of its union) simultaneously sues the government to get an injunction to block enforcement of the relevant civil rights law. From a district court decision that consolidated the two suits and declared the seniority system illegal but refused to impose financial penalties on the union, the corporation appeals and the government and union file cross appeals from the decision in the suit brought by the government. Assume the case was listed in the Federal Reporter as follows:
  United States of America,
  Plaintiff, Appellant
  v
  International Brotherhood of Widget Workers,AFL-CIO
  Defendant, Appellee.
  International Brotherhood of Widget Workers,AFL-CIO
  Defendants, Cross-appellants
  v
  United States of America.
  Widgets, Inc. & Susan Kuersten Sheehan, President & Chairman
  of the Board
  Plaintiff, Appellants,
  v
  United States of America,
  Defendant, Appellee.
  This case should be coded as follows:Appellant = United States, Respondents = International Brotherhood of Widget Workers Widgets, Inc., Total number of appellants = 1, Number of appellants that fall into the category "the federal government, its agencies, and officials" = 1, Total number of respondents = 3, Number of respondents that fall into the category "private business and its executives" = 2, Number of respondents that fall into the category "groups and associations" = 1.
  Your task is to identify the state of the first listed state or local government agency that is an appellant.
choices: not Alabama Alaska Arizona Arkansas California Colorado Connecticut Delaware Florida Georgia Hawaii Idaho Illinois Indiana Iowa Kansas Kentucky Louisiana Maine Maryland Massachussets Michigan Minnesota Mississippi Missouri Montana Nebraska Nevada New New New New North North Ohio Oklahoma Oregon Pennsylvania Rhode South South Tennessee Texas Utah Vermont Virginia Washington West Wisconsin Wyoming Virgin Puerto District Guam not Panama