How long can a cop follow you before it's considered harrassment?

My son was followed for over a half hour. This is a small town, so he turned down many streets, even alleys and was still followed without ever getting pulled over! Is that legal? He feels it was harrassment.

Not sure that the mere act of following constitutes harassment.

One time I was driving through Coppell TX and going through one of those intersections that had a left turn arrow that was green for about 10 seconds and then red for 5 minutes I sped through the turn to beat the light. I made the light before it turned red but my quick turn caught the attention of a policeman who followed me all the way to the city limits sign. Now I often find myself followed by a police car when I drive through Coppell. I'm sure they are just waiting for me to do something they can write me up for but so far they got nothing on me. I drive a sports car so I'm used to getting a lot of attention from the police.

 
Since your profile indicates that you are only 13, I doubt that you have a son that is old enough to drive.

However, the police may have been suspicious of the vehicle or its occupants and therefore tailed it looking for a reason to pull it over.

If I found myself in that circumstance I would simply pull into a public place like a convenience store or hamburger stand and just sit there until the police chose to leave. If they chose to also pull into that parking lot then I'd walk back to them and politely ask them if there was something I was doing wrong that was causing them to follow me.

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