A pretrial detention hearing in federal court is much like a bail hearing in state court. It's a hearing at which the court determines whether to detain the defendant without bail.
The prosecution must bring a motion to initiate a detention hearing. These hearings—typically held at the first court appearance—are reserved for certain kinds of cases, including:
A detention hearing is also required if there is a serious risk that the accused will flee or interfere with the judicial process in any way, including by intimidating witnesses or jurors. (Id.)
The defendant has a right to an attorney at a detention hearing. The defense is entitled to cross-examine witnesses and present evidence.
In deciding whether bail is appropriate, the court considers whether there are any conditions (such as a particular bail amount or monitoring by the government) that will ensure that the defendant, if released from custody, will show up for court in the future. The judge will also consider whether the defendant's release will compromise the safety of any particular people or the community at large.
If you face a bail or detention hearing, seek the help of an experienced criminal defense attorney. Only such a lawyer can adequately represent you at this stage and throughout the proceedings.