You may hear reference to a previous trial of this case. A previous trial did occur. But [defendant] and the government are entitled to have you decide this case entirely on the evidence that has come before you in this trial. You should not consider the fact of a previous trial in any way when you decide whether the government has proven, beyond a reasonable doubt, that the defendant committed the crime.
(1) This instruction is derived from Ninth Circuit Instruction 2.09, Federal Judicial Center Instruction 14, and Sand, et al., Instruction 2-13. The commentary to the Ninth Circuit and Federal Judicial Center instructions both recommend that this instruction not be given unless specifically requested by the defense. See also United States v. Seals, 987 F.2d 1102, 1109-10 (5th Cir. 1993) (finding it was not error to fail to instruct the jury when defense counsel refused trial court's offer to give instruction following inadvertent references to the defendant's previous trial).
(2) The District of Columbia Circuit has suggested that the following cautionary instruction be given at the outset of a retrial: "The defendant has been tried before. [If there has been a mistrial, so state.] You have no concern with that. The law charges you to render a verdict solely on the evidence in this trial." Carsey v. United States, 392 F.2d 810, 812 (D.C. Cir. 1967) (finding defense counsel's mention of "mistrials" did not substantially prejudice the prosecution and prevent a fair trial, so that the trial judge should have handled the matter through a cautionary instruction instead of declaring a mistrial); see also United States v. Hykel, 461 F.2d 721, 726 (3d Cir. 1972) (affirming instruction given after mention during jury selection of previous mistrial; instruction cautioning jury that "[T]he fact that this is the second trial of this case should mean nothing to you. Do you understand that? No inference of any kind should be drawn from that."); cf. United States v. Faulkner, 17 F.3d 745, 763-64 (5th Cir. 1994) (affirming court's statement to jury about true reason for mistrial in context of newscasts erroneously reporting that previous trial ended in mistrial due to jury tampering).