Under the 1984 Bail Reform Act, a judicial officer finding probable cause to believe that the arrestee has committed a serious crime as defined in the act, may require pretrial detention. The court, upon motion of the U.S. attorney, is required to hold a hearing to determine whether any condition or combination of conditions will reasonably ensure the trial appearnce of the arrestee and community safety. In the hearings held thus far, defense counsel generally challenges the Government's evidence of prior criminal record and representations that the defendant would endanger the community if released prior to trial. Both the prosecution and defense have a right to appeal the judicial officer's ruling, and the judicial officer may amend the order at any time or impose additional or different release conditions. Temporary pretrial release under custody may be deemed necessary for defense preparation. The act favors the defendant by prohibiting the judicial officer from imposing a financial condition the defendant cannot meet. Also, the act imposes additional penalties for failure to appear at trial, penalties that are consecutive to any incarceration sentence. Although it is too early to assess whether or not the act will increase the prison population and encourage more guilty pleas, early reports from several Federal prosecutors indicate an increase in guilty pleas where the defendants have been temporarily detained before trial. Fourteen footnotes are listed.