checkpoint
accident
auto
automobile
block
blue
car
commotion
crime
crowd
danger
delinquent
demonstrator
department
enforcement
event
fine
flashing
force
law enforcement
light
lightning
lights
motorcar
patrol
people
person
police
police department
policing
protest
protester
protestor
raid
revolt
riot
rioter
rioters
road
robbery
security
siren
sirene
sirens
theft
traffic
transport
transportation
uniform
uprising
vehicle