Hello...

If an investigation is going on for 4 or more years... and the investigators are using

This person's family's license plate numbers ( other vehicles in the family) plus her own
To watch this person whever she goes... is this legal ?

Would they be using gps or cameras ? Are thet detectives ?

Thank You

Are you asking whether it's legal for one person to follow another when out in public, driving around? Sure, why not - as long as there is no harassment or intimidation going on, when you are in public there is no law to prevent others from following you.

However - it IS illegal to bug the person or his/her car, and the courts are beginning to tighten restrictions on whether the police can use GPS trackers on a person's car without a warrant. Thus while no warrant is needed to follow someone in public, a warrant may be required if the "eyeballs" of a cop are replaced by an automatic electronic device like a GPS tracker.

I'm not sure if this answers yuor question or not - can you provide more specifics as to what exactly is the scenario here?