Image Sensing Surging In The #PreMarket

Shares of Image Sensing Systems ISNS are up another 42 percent, adding on to Tuesday's 43 percent gain.

Image Sensing develops and markets radar and video processing for use by security and police, and the recent unrest in Ferguson, Missouri has brought its products to the forefront.

Two other police video security stocks, Digital Ally DGLY (up 76 percent) and Vicon Industries VII (up 100 percent) have also had enormous gains the past two days.

Image Sensing was last up 42.8 percent at $3.40 in the pre-market session.