Who Can Testify to the Calibration of Breath Testing Machines?
The issue of who is required to, or can, present testimony regarding the calibration of the breath testing equipment arose in State v. Smith, 1999-NMCA-154. In that case, the officer who administered the driver’s test was not the key operator/officer who performed the required weekly calibrations. This is common in many DWI cases: most officers will be certified to administer tests on the breath machines, but each law enforcement agency will only have a few officers who are SLD-trained as key operators. Again, key operators are persons who are trained to run the required weekly calibration checks on the breath testing equipment. The standard method of proving the machine was properly calibrated within the required time limits is for the prosecution to introduce into evidence the written log book entries that show all weekly calibrations, as well as all actual drivers’ breath tests performed on a given machine. It is common to introduce only those pages of the log book that cover the we
