Frisco DWI Lawyer & Attorney Blog
A great point was made recently by Jamie Spencer (through George Scharmen at the Rusty Duncan Criminal Defense Seminar put on by TCDLA) regarding the cross examination of an officer about HGN.
Jamie points out in "Nystagmus, Mostly Leave it Alone" that not a lot of cross examination is necessary. Mark Bennett agrees in his comment that "juries are duly unimpressed with the ‘pen voodoo’ as one juror called it post-trial."
Here is my take on it: