Police patrol oversight is centralized, active, and direct: At its own initiative, Congress chooses a sample of executive agencies with the aim of detecting and remedying violations of legislative goals, and by its surveillance, discouraging such violations.
Police patrol oversight, like its namesake, is the routine work of "patrolling" the executive branch looking for problems in program implementation. It is usually centralized in a legislature in an audit or program review committee with a staff agency that evaluates the performance of executive agencies. It relies on formal committee hearings on agency operations and on interim studies and reports on legislative performance. Police patrol oversight is usually initiated by the legislature and tends to be formal and systematic.
McCubbins and Schwartz contract this to what they call police patrol oversight, in which legislators conduct routine patrols exploring the implementation of programs. They contend that the approach produces oversight that is much more effective: through periodic interventions sparked by apparent problems, members of Congress con more clearly define the goals they have in mind. Moreover, they contend, responding to problems as they arise is much more likely to detect troubles than is maintaining a regular police-patrol style.
Fire alarms oversight is less centralized, less active and direct: Congress establishes rules, procedures and informal practices to enable citizens and organized interest groups to examine administrative decisions to charge agencies with violating congressional goals and to seek remedies from agencies, courts and Congress itself.
Fire alarm oversight of executive programs by legislatures occurs when interest groups complain about how programs are administered, the media expose programmatic waste or abuse, or constituents report problems with government services that reveal flaws in program design or implementation. It is highly decentralized, relies on outside actors to "sound an alarm", and is less than systematic.
Some suggest that the fire-alarm style missed the opportunity to fix little problems before they become big one and that it encourages legislators to play for the issues most likely to attract the cameras. Oversight is a much more subtle process than the formal checks and balances system might suggest.
Fire alarms are more effective because legislative goals are stated in an ambiguous way that obstruct violation detection, unless third parties complaint. Fire alarms are focused in the sense that identifies the specific offended agency or citizen, a matter that police patrol would not do.