Could have been a UV or NIR laser. Tucson have a significant number of optical engineering companies plus the Optical Sciences Center at the U of A and a large Raytheon plant that specializes in electro-optics. An engineer could have tried to aim a UV or NIR laser from a location outside the event perimeter at Trump. Since the beam from these wavelengths are invisible, it would be difficult to accurately point the laser directly onto President Trump.
“An engineer could have tried to aim a UV or NIR laser from a location outside the event perimeter at Trump.”
It was an indoor event so it would have had to be someone in the auditorium.
The device used could easily be camouflaged to resemble a camera or cell phone. Thousands of which are typically aimed at the dais when a speaker is up.
So, who manufactures that device? (China...)