I often get asked what some of the terms I tweet are. Whether you’re following me on Twitter or you’re listening to the scanner yourself here are some often used codes that might help. Different agencies do use slightly different codes but these should be a good starting point.

Code 3 – Units requested with lights and sirens
Code 4
– The event is over
Code 6 – Officers are out of the vehicle on foot
Code 37 – Vehicle reported stolen

Technically these are penal codes that get used as police codes
187 – Homicide
211 – Robbery
415 – Disturbance

KMA – End of transmission (may stand for Keep Me Advised)
TC – Traffic Collision
TA – Traffic Accident
PR – Person Reporting
RP – Reporting Party
RA – Rescue Ambulance
BLS – Basic Life Saving (ambulance)
ALS – Advanced Life Saving (ambulance)
ADW – Assault with a Deadly Weapon
OIS – Officer Involved Shooting

Following – Police are following a bad guy but haven’t yet initiated a stop or designated it a pursuit. I often mention these because it’s a real possibility that a pursuit will follow.
Pursuit/Chase – Police tried to pull over a bad guy and the bad guy did not stop and fled

Enjoy and happy scanner-ing!