opinion: SWYGERT, Circuit Judge.
  Defendant Darrell Eugene Lawson appeals from his conviction on one count of extortion that affected interstate commerce and one count of assault of a federal officer with a deadly weapon. He argues that lay testimony on the issue of his sanity was improperly admitted, that hearsay evidence in the testimony of the Government’s psychiatric expert denied him the right to confront adverse witnesses, and that he had the right to a government-appointed psychiatrist. We affirm his conviction.
  I
  In January 1980, the employees of the International Harvester Company were on strike. On January 29, Jimmy D. Dickey, the chief of plant protection at the company’s East Moline, Illinois plant, received a telephone call from an unidentified male who told him that he had information about damage that was going to occur to one of the company’s plants. Dickey contacted the FBI and made arrangements for future telephone calls to be recorded. The unidentified male, who was later identified as defendant Lawson, called again the next day. During this conversation, Lawson stated that “they’re hitting every plant that’s on strike.” He said that a group of men were planning on doing between one and one- and-one-half million dollars damage to International Harvester plants in Canton, Ohio, Louisville, Kentucky, and East Mo-line. Lawson demanded $50,000 for the information he possessed. He mentioned that he had worked for International Harvester, but that he had been fired. The money, he said, was his way of gaining revenge.
  When Lawson called again on February 1, he said that he would write out the information he had in detail, but that he would omit all names. He did not want to give any names in case one of the group backed out, and he did not want them arrested. Lawson said the group had contacted him because of his expertise in the field of explosives. He agreed to meet with Dickey and a man from the Treasury Department. In a phone call the next morning, Lawson informed Dickey the meeting would take place on Wednesday, February 6, near Ophien, Illinois. He gave Dickey specific instructions to get to the meeting place. When Dickey arrived near the site, he was to call Lawson on a CB radio. Lawson said his handle would be Mr. Spock, “just like Star Trek.” Dickey’s was to be Captain Kirk, and the man with him was to be Dr. McCoy.
  On February 6, FBI Special Agents David Hirtz and Joseph Ondrula followed Lawson’s instructions and met Lawson along a roadside. Lawson was wearing a blue ski mask, and he kept his right hand in his pocket. Hirtz told Lawson he was Dickey’s boss from Chicago. Lawson then handed Hirtz a note that read,
  Gentlemen, in the course of human events there comes a time of distrust. I don’t know if you are going to try or even thinking of trying to rip us off. But be warned there are two 300 Winchester Magnums aimed at your heads right now. If you live up to your end, we will live up to ours. Thank you.
  Hirtz told Lawson the money was three minutes away and that he would get it as soon as he had verified the information. Hirtz then read four pages of the information handed him by Lawson, who told him that he was the person who had made the telephone calls to Dickey. When Hirtz finished reading, he signaled to Special Agent Cullen Scott to bring the briefcase containing the money. Lawson was shown the money; he then handed Hirtz the last page of the information. Lawson said that he saw a gun in Scott’s belt. As Lawson stepped back and reached in his pocket, Ondrula shouted, “FBI,” and dove for Lawson. In the ensuing scuffle Lawson fired a gun at Scott and missed. Hirtz and Ondrula were able to subdue Lawson. In addition to the .38-caliber handgun that was fired, the agents found another loaded .38 in Lawson’s right coat pocket. Lawson waived his rights after arrest and admitted, among other things, that he was the one who had called Dickey.
  The two-count indictment was filed on March 5, 1980. Lawson was found to be indigent, and the court appointed counsel to represent him. Lawson defended on grounds of insanity. After a two-day trial, the jury found him guilty on both counts. Lawson was sentenced to twelve years on the extortion count and eight years concurrently on the assault charge. Both sentences were suspended, however, and reduced to 180 days in confinement and five years on probation. He was released on this sentence two weeks later.
  II
  Lawson’s principal contention is that the admission of hearsay in the testimony of the Government’s expert psychiatrist violated his right to confront adverse witnesses. During the pretrial proceedings, Lawson was examined for three months at the Federal Medical Center in Springfield, Missouri. Dr. Robert B. Sheldon, chief of psychiatry at the Center, testified on the Government’s behalf at trial that Lawson evidenced no symptoms of mental illness and that he was aware his conduct during the extortion attempt was not in conformance with the law. Dr. Sheldon admitted, however, that he did not have much contact with Lawson while he was at Springfield. He never interviewed Lawson privately, although he occasionally spoke with him informally, and he participated in only two staff interviews at which Lawson was present. Dr. Sheldon testified that two other physicians spent several hours each with Lawson in private interviews and that other members of the staff observed him during his stay. Dr. Sheldon thus based his testimony on reports he received from these physicians and other staff. He also stated that he relied on the results of tests administered at the Center, information received from the United States Marine Corps (of which Lawson had been a member), reports from the FBI, and “a large amount of information” furnished by the United States Attorney’s Office. None of this information was ever introduced into evidence.
  Lawson’s trial attorney objected in a timely manner that Dr. Sheldon’s opinion testimony was without foundation since “he would be placing the opinions of other persons not qualified [as an expert] and not before the Court [or] the jury.” The district court overruled the objection and permitted Dr. Sheldon to state his opinion. Lawson now relies on United States v. Bohle, 445 F.2d 54, 69 (7th Cir. 1971), which held that a medical expert may not testify regarding his opinion if it is based on information obtained out of court from third persons, since such an opinion would depend upon hearsay. We agree with Lawson that the introduction of expert testimony based in large part on hearsay may raise serious constitutional problems if there is no adequate opportunity to cross-examine the witness. Under the circumstances in this case, however, Lawson had that opportunity, and his right to confront adverse witnesses was not violated.
  The adoption of the Federal Rules of Evidence in 1975 expanded the scope of expert testimony. Rule 703 expressly permits experts to base their testimony on evidence that would otherwise be inadmissible, so long as it is “of a type reasonably relied on by experts in the particular field in forming opinions or inferences upon the subject.” In Baumholser v. Amax Coal Co., 630 F.2d 550 (7th Cir. 1980), this court held that testimony of an expert geologist concerning a study he had conducted of structural damage to homes caused by blasting in defendant’s coal mine was properly admitted under Rule 703. Because a similar study had been conducted by the Atomic Energy Commission, the court found that the expert’s survey “more than satisfied the threshold inquiry as to whether other experts would rely on it.” Id. at 553. In this case, the information Dr. Sheldon relied on to reach his opinion — staff reports, interviews with other physicians, and background information from the Marine Corps and the United States Attorney’s Office — were clearly of the type that psychiatrists would rely upon in making a similar professional judgment.
  In criminal cases, a court’s inquiry under Rule 703 must go beyond finding that hearsay relied on by an expert meets these standards. An expert’s testimony that was based entirely on hearsay reports, while it might satisfy Rule 703, would nevertheless violate a defendant’s constitutional right to confront adverse witnesses. The Government could not, for example, simply produce a witness who did nothing but summarize out-of-court statements made by others. A criminal defendant is guaranteed the right to an effective cross-examination. “Cross-examination is the principal means by which the believability of a witness and the truth of his testimony are tested.” Davis v. Alaska, 415 U.S. 308, 316, 94 S.Ct. 1105, 1110, 39 L.Ed.2d 347 (1974).
  In addition to the reasonable reliance requirement of Rule 703, a criminal defendant must therefore also have access to the hearsay information relied upon by an expert witness. Without such access, effective cross-examination would be impossible. Rule 705, which provides that an expert need not disclose the facts or data underlying his opinion prior to his testimony unless the court orders otherwise, recognizes this requirement. The Advisory Committee notes to that rule state that it “assumes that the cross-examiner has the advance knowledge which is essential for effective cross-examination.”
  The record in this case indicates that Lawson had sufficient access to the information Dr. Sheldon used to reach his opinion. The reports from the FBI and the United States Attorney’s Office were provided pursuant to a standard Brady request, as were the final medical report from the Springfield Medical Center by Dr. Sheldon and the report of one of the psychiatrists who interviewed him privately. It is true that Lawson’s counsel did not have copies of the notes made by staff members at the Center that were placed in Lawson’s file and were reviewed by Dr. Sheldon, but since he did have most of the data Dr. Sheldon relied on, he had an adequate opportunity to prepare his cross-examination. Furthermore, Dr. Sheldon had had at least some contact with Lawson himself, even though he never interviewed him in private. Under these circumstances, we hold that Dr. Sheldon’s testimony did not violate Lawson’s right to confront adverse witnesses.
  ill
  Lawson contends also that lay testimony on the issue of sanity was improperly admitted. Three FBI agents, including Hirtz, testified over objection that they believed Lawson was sane at the time of the commission of the offenses. There is no question that the Government (or the defense, for that matter) may introduce lay testimony on the issue of sanity. Rule 701 of the Federal Rules of Evidence expressly permits opinion testimony by lay witnesses. Although the Government here presented Dr. Sheldon as an expert witness, it may, in rebutting an insanity defense, present only lay testimony. United States v. Kennedy, 578 F.2d 196 (7th Cir. 1978). Lawson’s only argument is that in this case the Government did not lay the proper foundation because the three agents did not observe him for a long enough period of time.
  To support this contention, Lawson cites only cases that were decided before the Federal Rules of Evidence became effective. These cases hold that while a lay witness may testify about the conduct, assertions, appearance, and manner of speech of the defendant, they may only state an opinion on an ultimate issue such as sanity when “the witness has been qualified by sufficient association with an opportunity to observe the subject.” United States v. Alden, 476 F.2d 378, 385 (7th Cir. 1973). The adoption of the Federal Rules, however, modified this requirement. The rules permit the introduction of substantially more evidence than was formerly admissible. They place great reliance on cross-examination, for much evidence is now admissible subject to cross-examination as a means of verification. It is then up to the fact finder to determine the weight to be attached to that evidence. No more foundation was necessary in this case to admit the opinion testimony of the FBI agents. On cross-examination of each of them, defense counsel pointed out that each had had the opportunity to observe Lawson on only one occasion. The jury was free to give that testimony, particularly in light of the expert testimony that was also heard, whatever weight it felt appropriate.
  IV
  Lawson finally argues that the district court improperly denied his motion for a court-appointed psychiatrist. In fact, however, Lawson was able to present a psychiatrist to testify as an expert on his behalf. Dr. Eric Ritterhoff testified that he had interviewed Lawson on two occasions and that he had had access to the reports from the Springfield Medical Center. Based on these observations, Dr. Ritterhoff stated that Lawson was suffering from a “manic depressive” mental illness that impaired his ability to conform his conduct to the law.-
  The record indicates that the Government paid for at least one of these interviews. Lawson now contends that if the district court had granted the funding, Dr. Ritterhoff would have had more opportunities to examine Lawson and would have been able to testify more precisely about Lawson’s insanity. Such hypothetical statements as to what might have been are not sufficient to warrant a reversal, particularly since Dr. Ritterhoff was in fact able to testify on Lawson’s behalf.
  Lawson’s motion for a court-appointed psychiatrist was heard on June 18, 1980, as one of many motions presented by the defense. The Government attorney left the room while this motion was heard, as required by statute. Before leaving, however, the attorney discussed the issue with the court and informed the court that Lawson had been able to post a $25,000 surety bond. Lawson argues that the statement amounted to illegal participation in the ex parte hearing. While we do not condone such interference by the Government, we cannot hold in this case that it amounts to reversible error. At the time of the hearing, Lawson had already undergone the extensive testing at the Springfield Medical Center, and he had already seen Dr. Ritterhoff once. Based on these facts, the district court was within its discretion in deciding that no more psychological testing was necessary.
  Defendant’s conviction is affirmed.
  . 18 U.S.C. § 1951.
  . 18 U.S.C. §§ 111, 114.
  . The Bureau of Alcohol, Tobacco and Firearms of the .Treasury Department has investigative jurisdiction over bombings.
  . He was examined pursuant to 18 U.S.C. § 4244.
  . Seven or eight staff members were present at each interview, which lasted approximately fifteen minutes each.
  . The text of Rule 703 reads in full:
  The facts or data in the particular case upon which an expert bases an opinion or inference may be those perceived by or made known to him at or before the hearing. If of a type reasonably relied upon by experts in the particular field in forming opinion or inferences upon the subject, the facts or data need not be admissible in evidence.
  . Lawson points out quite correctly that Dr. Sheldon never testified, and the district court never found, that this information was of the type reasonably relied upon by psychiatrists. The court must make such a finding in order to satisfy the requirements of Rule 703. United States v. Hollman, 541 F.2d 196, 201 (9th Cir. 1976); Bauman v. Centex Corp., 611 F.2d 1115, 1120 (5th Cir. 1980). We may take judicial notice, however, that psychiatrists customarily use such information to make a diagnosis. See Notes of Advisory Committee to Rule 703. The district court’s error, under the circumstances in this case, is harmless.
  . See, e. g., Weinstein’s Evidence, 703[03] at p. 703-18 (1980) (“In a criminal case, even though Rule 703 warrants the use of hearsay as a basis for an opinion, the constitutional right of confrontation may require that the defendant have the opportunity to cross-examine the persons who prepared the underlying data on which the expert relies.”)
  . United States v. Williams, 431 F.2d 1168, 1173 (5th Cir. 1970), aff'd en banc, 447 F.2d 1285 (5th Cir. 1971), cert. denied, 405 U.S. 954, 92 S.Ct. 1168, 31 L.Ed.2d 231 (1972).
  . Rule 705 provides in full:
  The expert may testify in terms of opinion or inference and give his reasons therefor without prior disclosure of the underlying facts or data, unless the court requires otherwise. The expert may in any event be required to disclose the underlying facts or data on cross-examination.
  . Brady v. Maryland, 373 U.S. 83, 83 S.Ct. 1194, 10 L.Ed.2d 215 (1963).
  . While United States v. Bohle, 445 F.2d 54 (7th Cir. 1971), is distinguishable on its facts from the present case, Bohle was written prior to the adoption of the Federal Rules of Evidence. To the extent, if any, it conflicts with this opinion, it is overruled. This opinion has been circulated to all the active judges of the court, and no judge voted that the matter of overruling be reheard en banc.
  . Rule 701, Fed.R.Evid., states:
  If the witness is not testifying as an expert, his testimony in the form of opinions or inference is limited to those opinions or inferences which are (a) rationally based on the perception of the witness and (b) helpful to a clear understanding of his testimony or the determination of a fact in issue.
  . See also United States v. Pickett, 470 F.2d 1255, 1258 (D.C.Cir.1972); Mason v. United States, 402 F.2d 732, 738 (8th Cir. 1968).
  . Even in United States v. Alden, 476 F.2d 378 (7th Cir. 1973), cited by the defendant, the court held that brevity of observation would not affect admissibility but rather only the weight of the evidence. Id. at 385.
  . 18 U.S.C. § 3006A(e)(l).
  . See United States v. Lincoln, 542 F.2d 746, 749 (8th Cir. 1976), cert. denied, 429 U.S. 1106, 97 S.Ct. 1138, 51 L.Ed.2d 558 (1976) (in determining the reasonableness of the defendant’s request for psychiatric services, the court may consider the results of other competency examinations).
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