If radar/laser was used then arguments can be made against accuracy of the device or if he was pacing you there had to be sufficient distance and observation. Your knowledge of the lights (flashing) may not be an effective defense because traffic violations are "malum prohibitum" (bad acts) that do not require intent (knowledge) that you were violating. Speeding in a zone clearly marked or that you had been to many times before.
So how can you defeat a speeding ticket?
Speed radar units need to be calibrated.
Records of calibration need to be kept.
Tuning forks need to be used to test these units regularly.
Tuning fork calibrations and calibration logs need to be done on the date speeding was alleged, and during the month of the violation alleged.
Certificates of calibration must be kept for the tuning forks.
There are many potential areas of errors in the great majority of speed testing devices:
Cosine error, batching error, panning and scanning errors, shadowing errors, errors from interferences (billboards, overpasses, CB radios, cell phone towers, radio towers), errors inside the police car (heater, A/C unit, fans, radios, computers, police radios), errors from improper placement of the radar unit within the police car, errors due to heat build up in the unit, errors due to cold build up in the unit, errors due to power surges by turning on or turning off the radar unit at the last minute to avoid a car's radar detection unit, errors from automatic car locking systems, errors from a laptop, errors from a cell phone, errors from a pager, errors due to mirror switch aiming, etc.
The officer needs to be questioned (cross examined) about all of this, in detail, before he can lay a foundation that this unit was in proper working condition and NO errors were made or occurred.
The real question comes down to can the government, the state, the people of the great state of X prove beyond a reasonable doubt and to the exclusion of every honest, common sense doubt that the radar unit was properly working on the date and time in question?
Can they prove beyond this burden (this is their burden not yours) that the officer appropriately administered and used this testing device so that it was accurate and reliable?
Because if they can not then they have not met their burden, and the Judge must acquit.
Talk to (consult with) a WA licensed lawyer as I am not licensed in WA.
Lawrence (Larry) Newman, D.C., J.D. Attorney at Law Doctor of Chiropractic Licensed in NY, PA, NJ, & FL http://www.ithacainjurylawyer.com http://www.ithacadwi.com The response herein is not legal advice and does not create an attorney/client relationship. The response is in the form of legal education and is intended to provide general information about the matter within the question. Oftentimes the question does not include significant and important facts and timelines that, if known, could significantly change the reply and make it unsuitable. Dr. Newman strongly advises the questioner to confer with an attorney in your state in order to ensure proper advice is received.
Knowing the street and having the the sign covered are contradicting arguments.
This is not legal advice. If order to give you legal advice i would need to see the Tickets and talk to the court first. Good luck:)
If it is important to keep this ticket off your record, I suggest hiring an attorney. An attorney can raise challenges to the citation including whether the radar unit used was calibrated, if the officer has the appropriate qualifications and if the officer included notes sufficient saying where the school zone was and where you were located. Additionally, the attorney can negotiate with the prosecutor for an amendment of the charge to something that will not go on your driving record. You may also be eligible for another deferred finding as you are allowed one every seven years. Usually the officer will include in his report that he is sure you were the only one in the radar beam and that is difficult to challenge since it flies in the face of the officers narrative.