It is mainly up to department policy as to whether officers can equip their personal vehicles with lights and sirens. Some departments allow it while others don't.
In my town, street officers are not permitted to equip their personal vehicles with lights and sirens. That is because when they are on duty, they have their police cruiser. While off duty, it is not probable that they would respond to any calls. Also if they are out and about and have a reason to respond to something, they use their cell phones, or alot of the officers in town take their personal radios with them while out so they can call for backup from an on duty officer.
Unlike some of the others said, there is no such thing as being truly off duty. When laws are being broke to the extent that needs immediate intervention, an off duty officer becomes on duty. And most all departments are decent about backing an off duty officer.
Detectives on the other hand are able to equip their personal vehicles with lights and sirens. That is because along with their shift, they operate on an on call basis.
But again, it is just department policy. Different police agencies have different needs that need to be met.
· 1 decade ago