Rambam - 1 Chapter a Day

From the comparison to the wording of the following halachah, one might think that this applies only with regard to the Supreme Sanhedrin. The Radbaz clarifies that this is not the case and the law applies to an ordinary Sanhedrin as well.

And in such a situation, this is unlikely to happen, for all of the judges rule that he is liable. Since the Torah’s criteria for execution- that there be “a congregation that saves,” i.e., judges who argue on the defendant’s behalf are not met, he is exonerated (Likkutei Sichot, Vol. 29, p. 166ff.).

For a majority of one is enough to exonerate a defendant (Chapter 8, Halachah 1).

For a majority of one is not enough to convict him (Ibid.).

One judge is not added, so that the court will not have an even number of judges.

Since it is as if this judge does not exist, it is as if there are only 22 judges on the court and 23 are necessary. Therefore, we make an addition.

The Radbaz and the Kessef Mishneh state that this judge can change his mind and decide to acquit the defendant, but cannot rule to convict him. From Chapter 10, Halachah 2, it appears that he can also, however, vote with those who hold the defendant liable at the time of the final judgment. Since he can change his mind, two judges are added and not only one.

The twenty-fifth judge says: “I don’t know.” This ruling has aroused the attention of the commentaries who a) question why the defendant is acquitted when there is not a majority of judges issuing such a verdict, and b) note that it appears to contradict his ruling a few lines later.
The Lechem Mishneh explains that since there are an ample number of judges who seek to acquit him, the fact that there are an equal number who wish to convict him is not significant. We follow the principle: With regard to doubt in cases involving capital punishment, we rule leniently.
The Tosafot Yom Tov (Sanhedrin 5:5) maintains that there is a printing error in the text of the Mishneh Torah and it should read: “Thirteen say that he should be exonerated and twelve say that he is liable....”

I.e., either the judge who originally said: “I don’t know” still maintains that position, or he changed his mind and adapted a different position, but another judge became doubtful.

As mentioned above, this clause appears to contradict the Rambam’ s previous statements. Some explain that in this instance, we are speaking about a situation where at the outset, there were twelve judges who ruled that he was liable and eleven who ruled that he should be acquitted. From the two judges who were added, one ruled that he should be exonerated, while the other said: “I don’t know.” In this instance, since originally, there was a majority voting in favor of conviction, the defendant is not exonerated because of the doubt and more judges are added (Radbaz, according to one interpretation).

I.e., we are unable to reach a resolution.

Since there is a doubt, we rule leniently and release him. The Meiri and others rule that the judges should continue debating until they come to a resolution.

This addition is made on the basis of one of the responsa of the Radbaz (Vol. V, Responsum 1690) who explains that this clause refers to a theoretical issue that relates to capital punishment, while the latter clause refers to an actual case involving a suspect brought before the court.

For we never make a court larger than 71, as stated above.