Fed. R. Evid. 606

(a) AT THE TRIAL. A juror may not testify as a witness before the

other jurors at the trial. If a juror is called to testify, the court

must give a party an opportunity to object outside the jury’s presence.

(b) D URING AN INQUIRY INTO THE VALIDITY OF A VERDICT OR INDICTMENT.

(1) Prohibited Testimony or Other Evidence. During an inquiry

into the validity of a verdict or indictment, a juror may not

testify about any statement made or incident that occurred

during the jury’s deliberations; the effect of anything on that

juror’s or another juror’s vote; or any juror’s mental processes

concerning the verdict or indictment. The court may not receive a juror’s affidavit or evidence of a juror’s statement on

these matters.

12 Rule 607 FEDERAL RULES OF EVIDENCE

(2) Exceptions. A juror may testify about whether:

(A) extraneous prejudicial information was improperly

brought to the jury’s attention;

(B) an outside influence was improperly brought to bear

on any juror; or

(C) a mistake was made in entering the verdict on the

verdict form.

(As amended Pub. L. 94–149, § 1(10), Dec. 12, 1975, 89 Stat. 805; Mar.

2, 1987, eff. Oct. 1, 1987; Apr. 12, 2006, eff. Dec. 1, 2006; Apr. 26, 2011,

eff. Dec. 1, 2011.)