This case requires us to determine whether the trial court abused its discretion when it ordered a new trial based on juror misconduct because a dismissed alternate juror sat in on jury deliberations. For the reasons that follow, we conclude that the trial court did not abuse its discretion.
A trial court may grant a new trial for various specified reasons, including an “[ijrregularity in the proceedings of the court, jury, magistrate, or prevailing party.” Civ.R. 59(A)(1). Even absent one of the grounds specified, a trial court may grant a new trial “in the sound discretion of the court for good cause shown.” Civ.R. 59(A)(9).
There is a rule of long standing in Ohio that a trial court ought not to “reverse a judgment because of the misconduct of a juror unless prejudice to the complaining party is shown.” State v. Hipkins (1982), 69 Ohio St.2d 80, 83, 23 O.O.3d 123, 125, 430 N.E.2d 943, 946. See Armleder v. Lieberman (1877), 33 Ohio St. 77, 1877 WL 165, paragraph one of the syllabus. We have applied this rule to a number of cases involving ordinary juror misconduct. State v. Sheppard (1998), 84 Ohio St.3d 230, 233, 703 N.E.2d 286, 290 (juror asked question of psychologist friend before beginning of deliberations); State v. Keith (1997), 79 Ohio St.3d 514, 527, 684 N.E.2d 47, 60-61 (juror discussed the jury process with non-jurors during trial); State v. Grant (1993), 67 Ohio St.3d 465, 480, 620 N.E.2d 50, 67 (juror asked a testifying detective “how he was feeling”); Hipkins, 69 Ohio St.2d at 83, 23 O.O.3d at 125, 430 N.E.2d at 945-946 (juror had brief conversation with witness). However, the case before us involves extraordinary misconduct where a stranger to the jury entered the jury room and remained there throughout the entire deliberative process.
Since this is a case of first instance in our state, we have reviewed several similar cases adjudicated in other states. One court has held that allowing alternate jurors to be present during jury deliberations for ten minutes is enough to taint a jury. Commonwealth v. Krick (1949), 164 Pa.Super. 516, 520-521, 67 A.2d 746, 749. Another court stated that alternate jurors “really are not jurors. When they attend jury deliberations they do so as mere strangers.” Commonwealth v. Smith (1988), 403 Mass. 489, 494, 531 N.E.2d 556, 559. See Brigman v. State (Okla.Crim.App.1960), 350 P.2d 321, 323. Still another court has stated that “any time an alternate juror is in the jury room during deliberations he participates by his presence, and whether he says little or nothing, his presence will void the trial.” State v. Bindyke (1975), 288 N.C. 608, 627-628, 220 S.E.2d 521, 533. Finally, several courts have written of the difficulty and dangers of inquiring into the prejudicial effect of an alternate juror’s presence in jury deliberations. United States v. Beasley (C.A.10, 1972), 464 F.2d 468, 470 (inquiry itself is dangerous intrusion into the proceeding of the jury); United States v. Virginia Erection Corp. (C.A.4, 1964), 335 F.2d 868, 871-872; State v. Cuzick (1975), 85 Wash.2d 146, 150, 530 P.2d 288, 290; Bindyke; Krick.
*252Were any of these factors the sole factor for the trial court to consider, it might have arrived at a different decision. However, the trial court was not confronted with a lengthy intrusion, or a stranger to the jury, or possible non-verbal communication, or the difficulty of determining prejudice. The trial court was confronted with all four.
The trial court was also aware of this court’s concern about the sanctity of jury deliberations. We recently stated, “ ‘Courts face a delicate and complex task whenever they undertake to investigate reports of juror misconduct or bias during the course of a trial. This undertaking is particularly sensitive where, as here, the court endeavors to investigate allegations of juror misconduct during deliberations. As a general rule, no one — including the judge presiding at trial— has a “right to know” how a jury, or any individual juror, has deliberated or how a decision was reached by a jury or juror.’ ” State v. Robb (2000), 88 Ohio St.3d 59, 81, 723 N.E.2d 1019, 1044, quoting United States v. Thomas (C.A.2, 1997), 116 F.3d 606, 618. See Virginia Erection Corp., 335 F.2d at 872 (“presence of the alternate in the jury room violated the cardinal principle that the deliberations of the jury shall remain private and secret in every case”).
Brownell’s improper presence likely was innocent and his influence may have been negligible. However, given its duration, his status as a non-juror, the possibility if not likelihood of non-verbal communication, and the difficulty of determining whether he prejudiced the jury, we cannot say that the trial court was wrong to grant a mistrial. To do so, we would have to find an abuse of discretion, which connotes an attitude by the court that is arbitrary, unreasonable, or unconscionable. Berk v. Matthews (1990), 53 Ohio St.3d 161, 169, 559 N.E.2d 1301, 1308. Our review of the record reveals nothing of the sort.
Our opinion does not abrogate the long-standing rule that juror misconduct should not be the cause of a reversal absent prejudice. Neither does it create a presumption of prejudice whenever an outsider invades the sanctity of jury deliberations. But, see, Bindyke, 220 S.E.2d at 531 (majority view is that the presence of an outsider during deliberations requires declaration of mistrial). Instead, we will continue to rely upon the sound discretion of our trial judges. When confronted with extraordinary circumstances, a trial court must be allowed to consider all of the pertinent circumstances in arriving at a decision. Given the circumstances in this case, the trial court did not abuse its discretion by granting a new trial.
Accordingly, the judgment of the court of appeals is reversed, and the cause is remanded to the trial court for a new trial.
Judgment reversed and cause remanded.
*253Moyer, C.J., Douglas, Fain and F.E. Sweeney, JJ., concur. Moyer, C.J., and Douglas, J., concur separately. Fain, J., concurs separately. Cook and Lundberg Stratton, JJ., dissent. Mike Fain, J., of the Second Appellate District, sitting for Resnick, J.