A Tactical Alert is defined in the
online LAPD Media Guide (a pdf document) as "
The preliminary stage of the Department Mobilization Plan. A Tactical Alert is an announcement of the anticipated redistribution of on-duty officers to achieve personnel levels necessary for controlling an emergency." Also check out Mobilization and Modified Tactical Alert on pages 24 and 28 in the glossary there.
What that basically means is that during a disaster or other emergency situation, officers in some or all divisions, as announced, confine their activity to "
police work of major importance" (see below), so they remain available to be deployed to the concerned incident(s) as needed. All urgent and emergency calls for service continue to be dispatched, but most
non-priority calls in affected divisions are not dispatched, but the callers are referred to their local division station to make reports. "Code 7s" (lunch breaks) and routine running of suspects and licenses over the radio are restricted.
A division Watch Commander, Field Commander or Communications Division can call for a Tactical Alert, and it's Communications Division that is responsible for broadcasting it on radio frequencies citywide and other internal communications networks, with a general description and location of the incident, which patrol areas and divisions are affected, and other relevant information. Communications Div also makes direct notifications to a number of specified department offices and personnel as well as outside agencies.
"Police Work of Major Importance" is defined in the
online Department Manual, Volume 0. Section 030 as "
police activities involving the arrest, processing, and detention of felony suspects and intoxicated drivers, and activities necessary to the immediate interest of public safety and protection of life and property. Investigations shall be limited to those activities which include felonies, deaths, serious injuries, and City‑property involved traffic collisions involving injuries or substantial property damage."
