Once they are charged there would not be an indictment. Either the grand jury or the judge says there is enough evidence to hold them over for trial. In a case like this they will most likely go through a grand jury.
The Fifth Amendment to the Constitution of the United States states in part: "No person shall be held to answer for a capital, or otherwise infamous crime, unless on a presentment or indictment of a Grand Jury, except in cases arising in the land or naval forces, or in the Militia, when in actual service in time of War or public danger..."
In many (though not all) U.S. jurisdictions retaining the grand jury, prosecutors often have a choice between seeking an indictment from a grand jury, or filing a charging document directly with the court. Such a document is usually called an information, accusation, or complaint, to distinguish it from a grand jury indictment. To protect the suspect's due process rights in felony cases (where the suspect's interest in liberty is at stake), there is usually a preliminary hearing where a judge determines if there is probable cause that the charged crime was committed by the suspect in custody. If the judge finds such probable cause, he or she will bind or hold over the suspect for trial.
The substance of an indictment or other charging instrument is usually the same, regardless of the jurisdiction: it consists of a short and plain statement of the time, place and manner in which the defendant is alleged to have committed the offense. Each offense is usually set out in a separate count. Some indictments for complex crimes, particularly those involving conspiracy or numerous counts, can run to hundreds of pages, but many indictments, even for crimes as serious as murder, consist of a single sheet of paper.
Indictable offenses are normally tried by jury, unless the accused waives the right to a jury trial. The Sixth Amendment mandates the right of having a jury trial for any criminal offense punishable by imprisonment for more than six months. Notwithstanding the existence of the right to jury trial, the vast majority of criminal cases in the U.S. are resolved by the plea bargaining process.