Originally Posted by
UNM1136
Ask any other cop anywhere what an HGN does for their DWI arrest, and they can tell you, but in NM we have been able use the HGN during our investigation (it is the most accurate field sobriety test we have, without a portable breath tester), and are allowed to use the results of our HGN in our custody decision, but we are not permitted to testify to the results of that test, nor the specific clues we are trained to look for in that test (but general, non-nystagmis related observation is fine). This decision (I think, without checking) is roughly 20 years old.