I would place a trigger zone (TZ) down the street. I would set the TZ's IF USED property box with the name of the entity you want to disappear (PoliceLine). Within the TZ's main ai script I would include:
:plrwithinzone=1:activateifused=1
Within the main ai script of the entity you want to disappear, I would set its name (PoliceLine) and within its main ai script I would include:
:activated=1:runfpidefault=2
If you want to make 3 objects disappear . Then change the ai of the trigger zone to :
:state= 0, plrwithinzone=1: settargetname=PoliceLine1, activatetarget=1, state=1
:state= 1, plrwithinzone=1: settargetname=PoliceLine2, activatetarget=1, state=2
:state= 2, plrwithinzone=1: settargetname=PoliceLine3, activatetarget=1, state=3
and name the 3 targets accordingly.
