ESD is a part of SEB (Special Enforcement Bureau-SWAT).  The unit is made up of 20

paramedic/deputies who are trained in SWAT operations (all members come from the SWAT unit), tactical ALS medicine, SCUBA diving, mountaineering, boat and helicopter operations.  Air-5 is the big search/rescue Sikorski that flies out of Long Beach and Angeles Crest.

Courtesy of Chris Young ESD