Dallas County area Police Officer Procedures and COC?

This is an area specific question, so anyone not from the Dallas County, TX area, please refrain from answering. If you must answer, please include viable references as to the Code of Conduct(COC) for this question.

Are police officers allowed to use radar guns while in motion? Or does this just depend upon what city or precinct they are employed?

Quite some time ago, i had heard that Arlington(Tarrant County, TX) police officers were no longer permitted to use radar guns while they were in motion. Apparently, there were some discrepancies about the safety of the radar's usage involving physical health because the officers would have the gun itself in their laps while they were driving on patrol.

That's really the main reason why i'm asking this question.

A second reason is that i received a citation for alleged speeding(45 in a 35), and the officer that passed me was in motion and stated on the citation that radar was used to assess my speed. I am already planning to plea nolo contendre(No Contest), with the option to take Defensive Driving. However, if the police officer was in direct violation of the Police Department's policies, i may push for dismissal. Not to mention that, while glancing in my left rear-view mirror, i also noticed that he performed a sudden U-turn(as he was in the opposite traffic) in front of two other vehicles that were following behind him.

Please...any useful information will be most appreciated.

Thank you.

WARNING: Any ridicule or malicious, immature behavior will be reported.