Opinion of the Court
Quinn, Chief Judge:The issue presented by the accused’s petition is whether his trial by general court-martial for larceny, and other violations of the Uniform Code of Military Justice, was barred by a previous trial for the same offenses.
Under the Fifth Amendment to the Constitution of the United States and the Uniform Code of Military Justice, no person may be twice put in jeopardy for the same offense. Consequently, if an accused is brought to trial before a court-martial and the proceedings are terminated after jeopardy attaches, but without legal justification, the accused is protected against another trial for the same offenses. Downum v United States, 372 US 734, 742, 10 L ed 2d 100, 83 S Ct 1033 (1963); United States v Schilling, 7 USCMA 482, 22 CMR 272. The first trial here ended after a Government witness had given part of his testimony; jeopardy, therefore, attached. United States v Wells, 9 USCMA 509, 26 CMR 289. However, the trial ended because the law officer directed a mistrial. A second trial does not violate the constitutional protection, if the first trial ended by reason of the proper grant of a mistrial; conversely, if the mistrial was improperly granted, a motion to dismiss is appropriate if the accused is again brought to trial on the same charges. United States v Stringer, 5 USCMA 122, 17 CMR 122; United States v Richard, 7 USCMA 46, 21 CMR 172. The accused moved to dismiss when arraigned the following day before another court-martial. The motion was denied. Determination of the validity of the ruling requires scrutiny of the circumstances which led to the grant of a mistrial at the first hearing.
During the challenge proceedings at the first trial, defense counsel asked the court members whether they knew Kang Tae Hyong, who was mentioned in three of the four specifications on the charge sheet. No one except the president admitted having any knowledge of Kang. The president said he knew “a Kang,” who was “at the orphanage,” but he did not know his full name. Defense counsel did not pursue the inquiry; nor did he attempt to establish, by other means, whether the Kang known to the president was the person mentioned in the specifications.
Kang was called as the Government’s first witness. After he testified that he had turned over Military Payment Certificates to the accused on two occasions in October 1963, his examination by trial counsel was interrupted by the president. He stated that he and all the court members now associated the witness with a person whose name had figured prominently in a different case, against another accused, which had been tried several weeks earlier. The law officer interpreted the president’s remarks as relating “back to the original question asked by the defense counsel” regarding the court members’ knowledge of Kang. Accordingly, he ruled that the matter could properly be considered at that stage of the trial as a “challenge for cause.” Cautioning against disclosure of such details that “might color the members’ positions,” he allowed further inquiry into the nature, and the effect, of the information possessed by the court members.
One of the senior court members indicated that, on the basis of the testimony he had heard in the previous ease, he had formed an opinion as to tho witness. Since the trial, additional information had come to his attention. What he had heard “affected” his ability to believe the witness. The examination of the members continued as follows:
“TC: Has any member of the court formed an opinion as to the witness’s credibility? Will the members please raise their hands?
*631“Let the record reflect that Captain Bosway, Major Alger, Colonel Gruenther, Major Rusche, and Captain Brandt raised their hands when trial counsel asked the question.
“Has that previous conviction, or will that previous conviction render you unable to believe this man today?
“LT COL GRUENTHER: You’ve already asked me that question. You’re not asking me are you?
“TC: I ask everyone on the court.
“MAJOR ALGER: It places some doubt in my mind.
“LT COL GRUENTHER: I’ve stated, perhaps.
“TC: Sir, I can only challenge all the members for cause.
“LO: Well, as to your last question, you had two responses I think. All except Colonel Barnes, is that right, sir?
“PRES: I wasn’t at the last one.
“LO: Now you have heard some discussion, though. I think you indicated that. Has that affected you the same way?
“PRES: Well, I’ve not heard discussion from the last court, but I’ve heard this individual discussed by some of the chaplains.
“LO: Does it affect you in the same manner as the others have indicated that it affects them as members of this court?
“PRES: Well, I think the very fact that all of the members of this court have had an opportunity to see what information this witness has produced in the past and raises doubt in all their minds, I’m liable to be affected the same way.
“LO: The question is whether the whole court should be discharged, so to speak, and start with a new court or have one left.
“PRES: I think I’m capable of accepting the testimony and not let the previous information affect my judgment of his credibility.”
The trial of a case may be halted, and a mistrial declared, whenever circumstances arise that cast substantial doubt upon the fairness or impartiality of the trial. United States v Johnpier, 12 USCMA 90, 30 CMR 90; United States v Shamlian, 9 USCMA 28, 25 CMR 290; United States v Stringer, supra. Courts have not attempted to mark out definitively the occasions that justify the declaration of a mistrial. Several circumstances have been judicially recognized as appropriate cause. One of these is when the triers of the facts are subject to such bias as not to be impartial. As the Supreme Court of the United States said in Simmons v United States, 142 US 148, 154, 155, 35 L ed 968, 12 S Ct 171 (1891):
“There can be no condition of things in which the necessity for the exercise of this power is more manifest, in order to prevent the defeat of the ends of public justice, than when it is made to appear to the court that, either by reason of facts existing when the jurors were sworn, but not then disclosed or known to the court, or by reason of outside influences brought to bear on the jury pending the trial, the jurors or any of them are subject, to such bias or prejudice as not to stand impartial between the government and the accused. ...
“Pending the first trial of the present case, there was brought to the notice of the counsel on both sides, and of the court, evidence on oath tending to show that one of the jurors had sworn falsely on his voir dire that he had no acquaintance with the defendant; and it was undisputed that a letter, since written and published in the newspapers by the defendant’s counsel, commenting upon that evidence, had been read by that juror and by others of the jury. It needs no argument to prove that the judge, upon receiving such information, was fully justified in concluding that such a publication, under the peculiar circumstances attending it, made it impossible for that jury, in considering the case, to act with the independence and freedom on the part of each juror requisite to a *632fair trial of the issue between the parties. The judge having come to that conclusion, it was clearly within his authority to order the jury to be discharged, and to put the defendant on trial by another jury; and the defendant was not thereby twice put in jeopardy, within the meaning of the 5th Amendment to the Constitution of the United States.”
In the usual case, the bias is directed in favor of, or against, a party to the cause. See United States v Walter, 14 USCMA 142, 33 CMR 354; United States v Smith, 6 USCMA 521, 20 CMR 237. It may be, as the accused implies in his brief, that a predisposition about a party cannot be classed with a predetermined prejudice as to a witness. For purposes of this appeal, we assume that an unalterable pretrial attitude on the part of the triers of the facts toward a particular witness is not ground for declaration of a mistrial in every case. It is certainly arguable that there is no “manifest necessity” to terminate the proceedings if the testimony of the proferred witness would merely be cumulative or relate only to a collateral matter. Cf. United States v Boyd, 7 USCMA 380, 22 CMR 170; United States v Dickenson, 6 USCMA 438, 20 CMR 154. However, if the witness is necessary to a party’s case, the situation is more like prejudice toward a party. In that instance, the testimony of the witness may, like the testimony of the party, be determinative of the case. Consequently, prejudgment of such a witness by the triers of the facts is as discrediting to the fairness of the trial, and as obstructive to the ends of justice, as preexisting prejudice for, or against, a party.
As noted earlier, Kang was named in three of the four specifications on which the accused was arraigned.1 Although he testified only briefly, it was obvious he was an important witness, and his testimony would be material to the issues that would probably be submitted to the court members for determination. The record demonstrated, therefore, that a fixed bias toward him would have the same destructive effect on the fairness of the trial as a preexisting prejudice for, or against, the party presenting him. The question then is whether the court members held a previously formed opinion of Kang which would influence them in their deliberation on the merits of the case. See United States v Deain, 5 USCMA 44, 17 CMR 44.
Five of the six members of the court-martial specifically indicated they had formed a previous opinion as to King’s credibility. The sixth member,, the president, stated he had information about Kang, and he was “liable to be affected the same way” as the others. Previous impressions of a court member are not automatically disqualifying. The member may continue to sit “if it is plainly demonstrated that such impressions will easily yield to the evidence presented in open court and to the law propounded by the trial judge.” United States v Deain, supra, page 49. The willingness of all the members to put aside their previously formed opinion of Kang was not “plainly demonstrated.”
The president of the court-martial declared he had not actually formed an opinion as to Kang’s credibility. He said further that he believed he v?as “capable of accepting the testimony” and would “not let the previous information affect . . . [his] judgment of . . . [Kang’s] credibility.” None of the others, however, would go that far. The member next senior to the president said only that he could “[p]erhaps” disregard his previous opinion of Kang. Another member indicated there was “doubt in . . . [his] mind” that he would be uninfluenced by his previous opinion of *633Kang. The record does not specifically reflect the responses of the remaining three members to trial counsel’s question as to whether their previous opinion would “render . . . [them] unable to believe this man [Kang] today.” However, without objection by any of them, the president said that the previous knowledge of Kang possessed by the court members “raises doubt in all their minds” that they could assess his credibility on the basis of his trial testimony.
On this evidence, the law officer could reasonably conclude that the opinion of Kang entertained by the court members was not casual or transient, but one of “such strength and endurance . i . as to . . . yield only to great persuasion.” United States v Deain, supra, page 52. Thus, the law officer was faced with a situation in which five of the six members of the court could not, in the interest of justice, continue to sit on the case. He also had to consider what effect this unanimity of opinion on the part of those who had sat on the other case would have on the remaining member. See United States v Richard, supra. Had only one member of the court been biased against Kang, the problem may perhaps have been solved by excusing him, and instructing the remaining members not to be influenced by his opinion. See United States v Batchelor, 7 USCMA 354, 22 CMR 144. With five of the six members definitely disqualified, and a fair risk apparent that the sixth member might be influenced by their collective opinion, the law officer had good reason to go beyond trial counsel’s challenge. The situation was not one of a reduction in the membership of the court below the required number. See Manual for Courts-Martial, United States, 1251, paragraph 41f. It was, as the law officer correctly observed, a “question . . . [of] whether the whole court should be discharged.” In United States v Morris, Fed Cas No. 15,815, cited with approval in Simmons v United States, supra, at page 154, the court said: “ ‘It is an entire mistake to confound this discretionary authority . . . to protect one part of the tribunal from corruption or prejudice, with the right of challenge allowed to a party.’ ” In our opinion, therefore, the law officer had a substantial reason to direct a mistrial. Consequently, the defense motion at the second trial to dismiss on the ground of double jeopardy was properly denied.
The decision of the board of review is affirmed.
Judge Kilday concurs.The dissent contends that, since Kang did not testify as to one offense, there was at least “jeopardy with respect thereto.” In military law, all known offenses should be tried together; consequently, the law officer was justified in treating this offense as part of the general issue. See Downum v United States, 372 US 734, 742, 10 L ed 2d 100, 83 S Ct 1033 (1963), dissenting opinion, Mr. Justice Clark.