
Quoting
BELLEVUE v. MOCIULSKI
In fact, the authentication of the speed measuring device involves a compound determination. Before the machine is deemed reliable, the witness testing the machines or monitoring the testing must first show his/her qualifications to make and/or evaluate the tests. The witness must first qualify as an expert via knowledge, skill, experience, training, or education. ER 702. After the witness has qualified as an expert, he/she must show that the machines passed the requisite tests and checks. Only then can the speed measuring devices be deemed reliable.