This law replaced the Bail Reform Act of 1966 and changed the rules for detaining defendants before their trials. In the four districts, results indicated that: (1) about 26 percent and 31 percent of the defendants were detained while awaiting their trials under the old and new laws, respectively; (2) a provision of the new law intended to aid in the detention of certain types of defendants considered dangerous or likely to flee before their trial was used to varying degrees; (3) under both the old and new laws, a small percentage of defendants failed to appear for a judicial proceeding or were arrested for committing a new crime while released on bail; and (4) court officials interviewed believed the new law was generally an improvement over the old, but about half of them expressed concern over the time needed to attend detention hearings that are required by the new law.