You shall set up judges and law enforcement officials for yourself in all your cities that the Lord, your God, is giving you, for your tribes, and they shall judge the people [with] righteous judgment.

שפטים ושטרים JUDGES AND BAILIFFS — שופטים are the judges who pronounce sentence, and שוטרים are those who chastise the people at their (the judges’) order [beating and binding the recalcitrant] with a stick and a strap until he accepts the judge’s sentence (Sanhedrin 16b and Rashi thereon; cf. Sifrei Devarim 144:6).

OFFICERS. Shoterim (officers) means rulers. It is related to shoter (ruler) in Overseer, or ruler (Prov. 6:6) and similarly mishtaro (dominion thereof) in the dominion thereof in the earth (Job 38:33). The shofetim (judges) judge and the shoterim (officers) force the crooked [to obey the law].

There are those who say that the police are the rulers, related to mishtaro (dominion thereof) in the dominion thereof in the earth (Job 38:33), and it is they who have the power and authority to carry out the judgment of the judges. Without them, the judges have no power or authority over the litigants at all, but only to instruct what the judgement should be. And after they have instructed, then it is the police who have the power and authority to strike and punish the guilty party, forcing them to accept the judgment. In which case, "achar mitzvasan" (according to the commands [of the judges]) means "according to their instruction", because [the judges] don't have the authority to command, but only to instruct...

So I took the heads of your tribes, men wise and well known, and I made them heads over you, leaders over thousands, leaders over hundreds, leaders over fifties, and leaders over tens, and officers, over your tribes.

"And officers I appointed..." - [Rashi's] intention is to separate it from the beginning of the verse, 'and I will take, etc.' wise men, etc. and I will put them, etc. and officers, etc.' Because it does not make sense that there would be a requirement that the officers have all the good qualities demanded of judges. Even according to the opinion in Tractate Makkot that one does not appoint overseers except for those lacking strength and exceeding in knowledge. Nevertheless, it is not reasonable that it would be the same as for the judges...

Chazzan - communal attendant. I have not heard any explanation of the meaning of the word.

HALAKHAH: They brought in the second,” etc. It was stated: “If they found him innocent, they freed him; otherwise they hold his case over, split into groups of two, eat little and refrain from wine, and discuss during the entire night. The next morning they start early, the beadles of the synagogues come for them...

"The chazzans of the community" - The attendants, through whom all the needs of the community are done, go to the place of the judges and call for them...

...R. Eleazar said, “If there is no law officer, there is no judge. How so? When someone is found by a court to have a legal obligation to his companion, if there is no law officer who will collect from him when he withdraws from the court, there is no power in the hands of the judge to do anything to him. If, however, [a law officer is present], he delivers him into the hand of the law officer, and the law officer extracts compliance from him.”

...Why did [Rashi] need to be explained [the functions of the judges and officers] like this? As if I don't understand the meaning of the words! And I would say, because it is written above in Parshas Devarim, "And I will give them leaders over you...and officers over your tribes." I would say that if judges are not found, then at least officers should be appointed, as it is written there, "and officers over your tribes," and it does not mention judges at all. Therefore, [Rashi] explained both here to imply that the police are dependent [on the judges], as the police officers are appointed solely for implementing the commands of the judges. And if there are no judges who determine the law, what is the need to appoint police officers...?

The reason why the Torah demands the appointments of law-enforcement officers is explained in Pessikta by Rabbi Elazar ben Shamua who says "If there are police, there are judges; if there are no police, there are no judges." Therefore, these words prove that if there are no police, there is no obligation to appoint judges. From this it can be deduced that whenever the Israelites know that the people do not obey the judges and the judges cannot compel them, there is no obligation to appoint judges. But whenever the people obey their judges without the need for police, they are obligated to appoint judges. And we call such a judge both a 'judge' and a 'police officer.'