underaged DUI

[troubled days]

What is the name of your state? Texas

Situation: I have a 17 years old son that was charged with a DUI in AR and need advise.
First Question: The cop that pulled him over did it for expired tags. Now the cop ran his tags out of city limits but pulled him over when he got into city limits. Can that resonible cause be used in court since the cop was out of the city limits (his jurisdiction) when he ran his tags?
Second Question? When he was arrested they did not read him his rights right then while being taken into custody. Does an officer have to read him his rights before taking him into custody?
Third Question: He did take a breathalizer but was told if he didn't he could be charged with another charge. Is this true?
Fourth Question: What is mostly likely going to be the punishment if convicted of the DUI in AR.

 

[The Occultist]

First Question: The cop that pulled him over did it for expired tags. Now the cop ran his tags out of city limits but pulled him over when he got into city limits. Can that resonible cause be used in court since the cop was out of the city limits (his jurisdiction) when he ran his tags?

Poorly worded, but I think you're asking if you can use this to get the charges dismissed. The answer is no.

Second Question? When he was arrested they did not read him his rights right then while being taken into custody. Does an officer have to read him his rights before taking him into custody?

Miranda warning is only needed post arrest, prior to interrogation. Not reading rights doesn't somehow magically negate the charges. If miranda warning is not given, then it only means that anything he says has a chance of being inadmissable in trial.

Third Question: He did take a breathalizer but was told if he didn't he could be charged with another charge. Is this true?

Yep.

Fourth Question: What is mostly likely going to be the punishment if convicted of the DUI in AR.

Some simple Googling oughtta get you the answer to that.