As I write this it seems pretty clear that CNN shat the bed by reporting that the FBI arrested a suspect in the Boston Marathon bombing and that there will be an appearance in federal court today.
Who knows when — or even if — an arrest and federal court appearance will happen.
But the media has been spewing inaccuracies about how it will happen, if it does. Here are a few things to keep in mind if the feds arrest someone and charge a federal crime. Federal criminal lawyers will find this oversimplified.
1. Federal prosecutions start in one of two ways: by a criminal complaint or an indictment. You get a complaint by presenting a federal magistrate judge with an affidavit explaining the facts establishing probable cause that the defendant committed the specified crime. You get an indictment by presenting a case to a grand jury. If an arrest happens soon, it will be by complaint. If it takes months, it could possibly be by indictment.
2. The feds will probably get an arrest warrant before they arrest a suspect. They will probably do that by filing an affidavit in support of a criminal complaint, as set forth above in (1). The feds could arrest someone without a warrant, but they won't unless emergency circumstances (like the suspect fleeing) arise. If they do arrest the suspect without a warrant, they'll immediately draft an affidavit in support of a criminal complaint and present it to a magistrate judge, as the defendant will be entitled to a prompt determination of probable cause after arrest. They will probably do that before the defendant's first appearance. So: if they arrest without a warrant, there will be a delay while they draft the affidavit.
3. The feds will probably try to interview the defendant. If the defendant is dumb or dumb-political and talks to them, the interview process will consume some time.
4. The defendant will be entitled to talk with an attorney before the first appearance. That will likely be a Deputy Federal Public Defender or someone from the local federal indigent defense panel. The first attorney meeting won't be extensive but will consume some time.
5. Pretrial Services — an arm of the court — will want to meet with the defendant. Pretrial Services' purpose is to gather information the court can use in making a bail determination. Here that's something of a farce; there's no way someone charged with this bombing will get bail. Nevertheless, Pretrial will go through the motions. The defendants' lawyers will tell Pretrial the defendant doesn't want to talk to them.
6. The arresting agent will have to get the office of the clerk to put the defendant on calendar before the magistrate judge on duty that day. How difficult that is depends on how busy the calendar is, which depends on who else has been arrested. Practically speaking, in a busy federal court like Boston, if the feds don't check in with the clerk by noon, it's very hard to get someone on calendar before the judge that day. Here the clerk's inclination to treat the case specially will conflict with all the complicating factors, causing a wash. Our defendant may not appear on the same day he's arrested unless he's arrested quite early. (Feds and locals everywhere love arresting people late morning Friday, which assures a weekend in custody with no bail determination. Some agencies love bringing in hordes of defendants as late as possible on Friday just, as far as I was ever able to determine, for the lulz. I'm looking at you, DEA.)
7. At his first appearance the magistrate judge will arraign the defendant. That means the judge will inform the defendant of the charges against him and his relevant constitutional rights. The judge will set a next court date. The government will ask the court to detain the defendant without bail, which the court will do. (Under the Bail Reform Act a federal defendant is entitled to bail unless no bail conditions will assure the safety of the community and the appearance of the defendant — here the judge will likely find both a flight risk and a danger to the community, no matter who the defendant is.) The defense may simply submit or ask for a delay of the bail hearing.
8. If the defendant was arrested based on a criminal complaint, and he's held without bail, he's entitled to a preliminary hearing within 14 days unless he's indicted. The feds will avoid the need for a preliminary hearing by indicting him first.
The bottom line is this: if there is an arrest, it's possible (or probable) the defendant won't make his first appearance the day of the arrest.