What part of the government enforces law?

Answer 1

Answer 1: The law enforcement part of government is its police force. However, the prosecuting attorney (aka, the "prosecutor" or the "district attorney," depending on where in the country it is), is considered the highest ranking law enforcement authority in whatever is the jurisdiction; and all police do basically whatever s/he says to do.

That suggests, though, that the prosecutor commands the police, and that's technically not the case, either. There is always someone in charge of the police. If it's a city or town, then the "police chief" is usually in charge of the police officers; and if it's a county, then the "county sheriff" is usually in charge of the county police officers (aka, deputies). If the jurisdiction is the state, then whomever is the head of the state police, or the state's bureau of investigation is usually the one in charge of state law enforcement officers.

Whomever is in charge of whatever are the jurisdiction's police officers is typically the one who talks with and kinda' follows the instructions and directions of the prosecuting attorney... be it at the county or state level.

If the jurisdiction is a city or town, or the county, then the "county prosecutor" (or sometimes called the "district attorney") is the highest-ranking law enforcement officer; and if the jurisdiction is the state, then the state's Attorney General is the highest-ranking law enforcement officer.

If the jurisdiction is the federal government, then the police officers include the FBI, the DEA, ATF, ICE, NCIS, and a long list of other federal law enforcement agencies; and the prosecutor, in that case, is the US Attorney's Office, which is operated by the US Department of Justice, which is under the command of the US Attorney General... which is a Cabinet position, appointed by the President of the United States.

It's important to understand that law enforcement is separate and apart from the Court -- or judicial -- system. Law enforcement officers, under the direction (either directly or indirectly) of the prosecutor, go out and collect evidence against people whom they believe have committed crimes; and then law enforcement arrests said persons and takes them to jail.

At that point, though, the Courts -- which is the judicial system -- takes over. The prosecutor is the lawyer for law enforcement, and the lawyer for the person who was arrested is the defense attorney. In Court, the prosecuting attorney and the defense attorney battle it out in front of the judge (and usually also a jury), and then either the judge or the jury (if there is a jury), decides if the one arrested is or isn't guilty. If the one arrested isn't found guilty then s/he is set free. If s/he's found guilty, then the judge figures out what sentence s/he should have (usually a fine plus jail, or just jail, or just a fine; plus court costs).

ADDED: While SOME of the information contained above is applicable, the short and direct answer to the question is: it is THE EXECUTIVE BRANCH of government that is responsible for enforcing the law.

Answer 2

Judicial