The American system of criminal procedure rests on the principle that the government should decide on the propriety of beginning all prosecutions, and then should bring and maintain, at its own expense, such as it may deem proper.

The first step ordinarily is the filing by an informing officer of a written complaint in the office of some court or with some magistrate, upon which a warrant of arrest issues as of course. In some jurisdictions original informations in a trial court, as distinguished from indictments, can only be filed by leave of court first obtained. Such is the rule in the courts of the United States.[Footnote: United States _v._ Smith, 40 Federal Reporter, 755.]

There is no such preliminary consultation with judicial officers as characterizes European criminal procedure. The prosecuting officer assumes the entire responsibility of initiating the prosecution and of giving it the particular form that it may assume. He commonly acts only on such matters as are officially brought to his attention by constables or other officers of police. It is rare that the party injured by an offense complains to him personally. Hence many of the lesser offences go unpunished, particularly in large cities, because the police fail to report them, on account of favoritism or corruption.

The warrant refers to the complaint for its support. Between them, the offense charged, the person accused, and the thing to be done by the officer who is to make service must be particularly stated. "General warrants," that is, warrants of arrest or seizure, not specifying the person who is to be arrested, nor the particular place where the seizure is to be made, are expressly forbidden by the fourth amendment of the Constitution of the United States as respects federal courts, and as respects those of the States, are generally prohibited by their Constitutions.

Any private individual may, by night or day, arrest without warrant one whom he sees committing a felony or a breach of the peace or running off with goods which he has stolen. If he knows that a felony has been committed and has reasonable grounds for suspecting that it was the act of a certain person, he may arrest the latter, although without personal knowledge of his guilt.

A sheriff, constable, or other peace officer may arrest without warrant any one whom he has reasonable ground for suspecting to be guilty of a felony, although it may turn out that no such felony was ever committed. For any ordinary misdemeanor he could not, at common law, arrest without a warrant, unless he personally witnessed the wrongful act or was near enough to hear sounds indicating what was being done.

In practice, officers of local police arrest freely on mere suspicion and with no personal knowledge either that any offense has been committed or that, if any, the person taken in charge was connected with it. The only risk which they run is of an action for damages, and that is slight. If one were brought and they showed that they acted in good faith and not wholly without cause, the amount recovered would probably be very small, and in any case it would be difficult to collect a judgment against one of them, as they are generally men of small means.